3NOIC13W JO Aava8H IVNOUVN
WAA L484L 1871
63160130R
3NI3ia3W JO Aavi^r- Vt
NLM  D5m73flT   5
               1 OF MEDICINE


   3noio3w jo  Aavaan ivnouvn
NATIONAL LIBRARY OF MEDICINE
snidicisw jo Aavaan ivnouvn
3NOIQ3W jo Aavaan iv
NATIONAL IIBRARY OF MEDICINE
NATIONAL LIBRARY OF MEDICINE
NATIONAL LIBRARY OF ME
NLM051473895 
jiNiDiasw jo Aavaan ivnouvn



\
3NOia3w jo Aavaan ivnouvn
3NiDia3w jo Aavaan ivnouvn
 
 
 
 
TREATISE   ON  VENTILATION:
COMPRISING SEVEN LECTURES  DELIVERED BEFORE THE FRANKLIN
             INSTITUTE, PHILADELPHIA, 1866-68.
SHOWING THE GREAT WANT OF IMPROYED METHODS
        OF VENTILATION IN OUR BUILDINGS;
GIVING THE CHEMICAL AND PHYSIOLOGICAL PROCESS OP RESPIRATION;
COMPARING THE EFFECTS OF THE YARIOTJS METHODS OF HEATING AND LIGHTING
                   UPON THE VENTILATION.
Illustrated by many Plans of at.t, classes op Public and Private Buildings
   Showing theib present Defects, and proposing the best means (in
         the Author's judgment) of Improving them.
,,r. Oon/^
By LEWIS  W.  LEEDS.      ^     ltVxrt
Mian's own "breath is his greatest enemy."
                                  I

            NEW YORK:

JOHN WILEY & SON,  PUBLISHERS,
            15 ASTOR PLACE.
               1871. 
r
               WAA



                197/



             Film   z,o3t*   Ho>l



Entered according to Act of Congress, in the year 1871, by
             JOHN WILEY & SON,
In the Office of the Librarian of Congress at Washington.
THE NEW YORK PRINTING COMPANY,
     81, 83, and 85 Centre St. 
PREFACE   TO  FIRST  COURSE   OF  LECTURES.
   These Lectures were not originally written with any view  to their pub i«
cation;  but  as they were afterwards requested for  publication in the Jour-
nal of the  Franklin Institute, and there  attracted very favorable notice, I
believed the rapidly increasing interest in the subject of ventilation would
enable the publishers to sell a sufficient number to pay the expense of their
publication; and, if  so, that this  very spirit  of inquiry  which would lead
to the perusal of even so  small a work, might be one  step forward towards
that  much-needed more general education on this  important subject.
   It was not  my desire to give an elaborate treatise  on  the  subject of
ventilation.   I  believed  a few general  principles, illustrated in a  familiar
way, would  be  much more  likely to  be  read;  and, I hoped, would act as
seed-grain in commencing the growth of an inquiry  which, when once started
in the right direction, would soon discover  the condition of the  air  we
breathe to be of so mnch importance that the  investigation would be eagerly
pursued.
                                                         L. W. L. 
 
PREFACE  TO  SECOND  EDITION.
So great has been the change, that, in revising these Lectures and adding
the Second Course for publication, it seems scarcely possible that two or
three short years only could  have passed since the general indifference
and apathy, as therein expressed, should have existed.
  But I remember  well it seemed  like a pall, a dead weight upon me,
that I could not arouse or shake off.  To be sure, that was in Philadelphia,
the slowest place for adopting new ideas in the country.  But  it is  very
gratifying, and pays for  many long years of labor and  discouragement,  to
see so radical a change in public sentiment, and so healthy a growth in the
true understanding and appreciation of correct principles of Ventilation, as
is every day developing  itself.
  It is a little  curious as well  as  interesting to watch the current  of
change in public opinion.   Less than ten years ago probably ninety-nine
out of every hundred thought the only place for the escape of the foul air
must be from the upper part  of  a room.  But, owing to the general adop-
tion of that national curse—hot air—it was found that in winter both the
heat and fresh air, being one, escaped through such  openings and  were
wasted.  Now, nine out of ten persons think the only place for such escape
should  be from the bottom, without any  reference  to the  manner of
heating.
   In a  short time the views of most persons will be changed, no doubt, on
this subject, as they have now commenced learning that all warmed air is
debilitating;—that we should breathe fresh, cool air, and be warmed  by
some other means,  say by radiation from open fires, or by exposed  pipes
heated  by circulating water or steam.
   The idea of warming the1 floors and exterior walls seems to strike  every
one as judicious, and is now being adopted and inserted in the plans oi
most of our new buildings.
   Then of course when we are receiving warmth from the solid  objects of a
room, instead of those objects absorbing the animal heat from our bodies, 
vi
PKEFACE.
the conditions are entirely changed; the fresh air may then  enter  cooler,
and will naturally flow under the fouler air that has  been longer  in the
'room, and will rise towards the ceiling in unison with that warmer and
fouler current that is always rising around and above the body.   Under
such conditions it is best to allow a liberal escape from the ceiling.
   It has been my endeavor to illustrate, as clearly as possible, this inti-
mate connection between the ventilation and warming, and to give  a suffi-
cient number of examples to assist the thoughtful student to start  on the
right track; being careful at the same time not to  assume that we have
already arrived at perfection in this particular, but remembering we have
but just commenced  the study of this important subject.
   I have  not  been particular, in selecting plans for illustration, to take
such only as  have  been  fully executed;  on the contrary, I have used
some which I think  will not be  executed at all.  Because with the pres-
ent very limited general  knowledge  upon the subject of ventilation, the
opinions of different individuals are so various and unreliable as to more
frequently lead astray than towards the exact truth,  and certificates or
opinions from interested parties, either in favor of or in condemnation of
the ventilation of any particular building, are of little value.
   Very frequently we find buildings in which the natural ventilation by
halls or large flues is excellent; yet  the same will  be condemned in the
strongest terms as entirely deficient in ventilationj  simply because there
is  not the show of registers or little twirly-bobs that many think so neces-
sary to produce good ventilation.
   On the contrary, nearly every architect has some good story to tell you
of how he has succeeded in securing  the most excellent results (upon the
minds of some Church committee or  owner of house) by putting large
ventilating registers in what he knew to be  the  solid wall or air-tio-ht
space over the ceiling.
   Therefore I have  made  but little attempt  to catch public notice bv
claiming some wonderful new invention, and getting a long list of  certifi-
cates from prominent men as to its great success;  but I have endeavored
more particularly to call  attention to general principles by which each
individual must be guided in his study of the important but complicated
problem, of how he shall, at all times and under all circumstances, supply
himself  with the necessary warmth and pure  air for the most perfect
physical existence and development,  relying more upon the acgreo-ate
result of a general agitation of the subject, than upon individual opinions
for my justification and encouragement. 
CONTENTS.
                        FIEST   COUESE.

                                LECTUEE  I.

Philadelphia a healthy city, 13 ; Owing to the superior ventilation of its houses,
    13;  But the theory of ventilation still imperfectly understood, 13 ;  About forty
    per cent, of all deaths due to foul air, 13; The death rate for 1865,13 ; Expense
    of unnecessary sickness, 13;  In London, 14; In Massachusetts, 14 ; In New
    York, 14 ;  In Philadelphia, 14;  Consumption the result of breathing impure
    air, 14 ; Entirely preventable, 14; Infantine mortality, 14 ; Report on warm-
    ing and ventilating the Capitol, 14; Copies of various tables therefrom,  15;
    Carbonic acid taken as the test, but not infallible,  15; The uniform purity of
    the external atmosphere, 15; Illustrated by the City of Manchester, 15 ; Over-
    flowed lands unhealthy, 16 ; Air of Paris, London, and other cities, 16 ; Carbonic
    acid in houses, 16 ;  Here we find the cause of  foul air,  17 ;  Our own breath is
    our greatest enemy, 17 ; Scavengers more healthy than factory operatives,  17 ;
    Wonderful cures of consumption by placing the patients in cow stables, 17 ; City
    buildings are unhealthy, consequently  air unhealthy,   18;  The air from  the
    filthiest street more wholesome than close bedroom air, 18; Unfortunate pre-
    judice against night air, 18; Dr. Franklin's opinion  of night air,  18 ; Compared
    with the instructions of the Board of Health, 1866, 19 ;  Sleeping with open win-
    dows, 20; Fire not objectionable, 21; A small room ventilated is better than a
    large room not ventilated, 21 ;  Illustration,  21; Fresh air at night prevents
    cholera, 21 ; Illustrated by New York workhouse, 22 ;   Dr.  Hamilton's report,
    22;  Night air just as  healthy  as day air, 22 ;  Candle extinguished by  the
    breath,  23; The breath falls instead of  rises,  24;  Children near the floor
    killed first, 25 ;  Physicians' certificates do not  state "killed by foul air,"  25 ;
    Open fire-places are excellent ventilators, 26 ; All fire-boards should be used for
    kindling wood, 26 ;  Illustrations showing where ceiling ventilation is necessary,
    27.

                                LECTURE  II.

The effect produced by heat upon the movements of air,  28  ; Air a real substance,
    28; Exerts  a pressure  of fifteen tons on an ordinary-sized man, 28; It cannot be
    moved without the expenditure of power,  28 ;  The sun's rays the great moving
    power, 28;  They pass through the forty-five miles of atmosphere without heat-
    ing it, and heat the solid substances  of the earth's surface, 29 ; Experiments
    showing the effect of radiant heat and reflected heat, 29 ; The air of the room
    not pure and dry, 32;  The ordinary moisture absorbs from fifty to seventy times
    as much as the air, 32 ;  Many gases absorb more, 32 ; The  moisture in  the  air 
s
Contents.
    the great regulator of heat, 33 ;  Air is heated by coming in immediate contact
    with hotter substances, 83 ; Impossibility of any air remaining at rest, 33 ; The
    practical application of these principles, 33;  The open fire  acts like the sun,
    heating by radiation only, 33 ; Probable electric  or ozonic change in furnace-
    heated air, 34 ;  The stove heats both by radiation and circulation, 34 ;  Neither
    the stove nor open fire suitable for heating large crowded rooms, 35 ; Circulating
    air partially warmed with exposed steam or water pipes for radiation best, 35;
    Erroneous views in regard to ventilation,  35 ;  Experiments with  liquids of
    different densities, 36;  When warming and ventilating by circulating  air, the
    escape for the used air should be from  the bottom of the room, 36 ; But when
    ventilating  with cooler air the escape should be from top of the room, 48 ;
    Windows should lower from the top, and flues open at the bottom of the room,
    43 ;  The fashionable system of heating by  direct radiation, without any fresh
    air, very objectionable, 44.


                               LECTURE III.

One  breath of impure air shortens  our life, 48 ;  Difficulty of gettmg  pure air to
    breathe in houses and cars, 48;  Foul air in steam cars, 48 ;  Want of the pro-
    per knowledge regarding ventilation among all classes, 49; Want of ventilation
    in this  lecture-room, 50; Want of  ventilation  in the Cooper Institute,  and
    in many other  new and splendid buildings,  50;  street cars very foul, 51;
    My own chamber fully ventilated, 51; I  have  no patent idea,  sufficient for
    all time without further thought, 51 ; Constantly varying conditions require
    separate intelligent  thought  and  action,  51  ; The air moves horizontally in
    summer, 52 ; Flues are then of no  account, 52 ; We  must depend on  open
    doors and windows, 52 ;  How  to ventilate a sick room in the morning, 52;
    The same in the evening, 52; Windows should always lower from  the top,
    52;  To make  the  air  move in  the summer is the great desideratum, 52 ;
    When in motion the cold air falls and warm air rises ; when at rest it is arranged
    in horizontal layers according  to temperatures, 53; A flue is simply a passage
    for air  of  different temperatures, 53; Experiments with  flues of different
    temperatures, 53 ; Expansion  of air by heat,  55 ; Weight required to keep  it
    from expanding, 55  ; Heating air weakens  it,  instead of giving it  power, 56;
    Experiments showing draughts by lighted candles, 56 ; Ventilation of churches,
    56 ; Illustrations not exaggerated, 57 ; Examination of church in neighborhood,
    57 ;  Fresh air  taken from foul cellar, 58  ; No  fresh air supplied to churches
    used as hospitals in Washington, 58; Depending on a  sham ventilator painted
    on the solid wall, 58 ;  Foul air in  Philadelphia schools, 59 ;  New York public
    schools, 59 ; Many of the ventilators perfect shams, 59 ; Covered up air tight
    by the capping  stones, 59;  Importance of  the evaporation  of water,  60 ;  A
    strong fire in basement will draw gas out of second story stove, 62 ; A strong
    fire up-stairs will draw foul gases  from untrapped sewers, 62; A very healthy
    location may thus be made very unhealthy, 63  ; Drs. Palmer, Ford,  and Earle's
    report of epidemic at Maple Wood Institute, 63 ;  An arrangement for ventila-
    tion that ought  to be in every  house, 63 ; Flues generally too  small, especially
    in Philadelphia, 64 ;  Very large ones put in government hospitals, which proved
    thoroughly efficient, 64;  The leading points  in  regard to heating, 64; The
    fresh air must be warmed before entering in winter,  64 ; A hot-water  furnace 
Contents.
9
requires additional moisture, 65 ; Heating by steam, 65; Steam-pipes ought to be
laid through the street, the same as gas and water, 65 ;  Two-thirds of heating
Burface should be for heating the fresh air, and one-third for direct radiation,
65 ;  Forty pounds of water required to be evaporated every minute for U. S.
Senate Chamber, 66 ;  All stoves should have fresh-air  boxes, 66;  Dampers
in fresh-air boxes not good, 66 ; Experience has fully demonstrated that careful
attention to these things will be amply rewarded by increased health, strength,
happiness,  and longevity,  67.
                      SECOND   COUESE.

                                LECTURE I.

Rapid decrease in rates of mortality, 69; Three-fourths of a million dollars saved
    annually,  69; More public education needed, 69;  Old-fashioned wood fires
    better ventilators than modern stoves and steam radiators, 70;  Physiological
    effect of breathing pure or impure air, 70 ; Surface of the lungs, 71 ; Color of
    the blood changed, 72 ; Choking of the air-cells causes consumption, 72 ;  Dia-
    gram illustrating immense quantity of air breathed daily, 73 ;  Diagram repre-
    senting quantity of blood daily circulated,  74 ; Effect of  exercise, 74;  Greatly
    increases circulation of the blood and air, 74 ; Excellent  medicine, 75 ;  Better
    than patent  pills, 75 ;  Not  only for  consumption,  but for all diseases and
    wounds, 76 ; Air, food, and exercise the three  grand essentials of health and
    happiness, 77 ;  Air ten times the importance  of food,  77; But without food
    you die sooner in pure  air than foul  air, 77;  Experiment with flies, 77;
    How delicate persons exist  to old age in foul air,  79 ; Pecuniary value  of
    health, 80 ; An unhealthy nation soon become paupers, 81 ;  The laboring men
    should be educated, 82 ; Each one of us  should be a lecturer on ventilation,
    82 ; Improvements in ventilation could be more easily effected in Philadelphia
    than in any • other city of the world, 82;  Physicians might help,  82;  But
    are too cautious, 83 ;  Extract from  Carpenter's Physiology, showing venti-
    lation to be of the greatest importance, 83;  States  one-half of all the  deaths
    caused by foul air, 84 ;  A herculean task to make the public comprehend it, 85 ;
    An extra ton of coal and blanket for each  family might save many lives, 85 ;
    A word to the people employing physicians, 86; Many prefer being humbugged
    with patent medicines to taking good advice from an honest physician, 86.


                                LECTURE II.

Composition of the air we breathe, 88 ;  Its' effects more easily related than compre-
    hended, 88 ; As shown by the close foul atmosphere of many rooms occupied by
    very intelligent persons, 89 ; When we learn to comprehend its marvellous effects
    we will look upon pure air as the greatest  of temporal blessings, 90 ; Experi-
    ment of passing the products of  a burning candle through  lime-water absorb-
    ing the carbonic acid; but the remaining air will not  support the combustion
    of  a candle for want of oxygen, 91 ;  Experiment  showing the similar effect
    upon the air of the fires in our bodies to that produced by the burning candle,
    92; But little known about the composition of air, 93 ; The doctors tell us half 
10
Contents.
the deaths are caused by foul air, and yet they are too busy disputing about the
effects of little doses  or  great doses of their medicines to study carefully the
analysis of  this killing air,  93 ;  The colder the air breathed the greater the
amount of carbonic acid exhaled, 93 ; The  carbonic acid from our breath twice
the normal amount to  one hundred times the air breathed, 94 ; The exhaled air
should be removed directly from the room, 95 ; The temperature of the body
remains uniform, 95 ;  The cooling effect  of  perspiration,  95 ;  Discharge  of
moisture through the pores of the skin, 96; " Taking cold," 97 ;  The human
system is filled with smoke or unconsumed carbon, like a smoky lamp, if not
supplied with oxygen,  97 ; An American receipt for killing yourself, 98 ; Simple
receipt for preserving good health, 98 ; Diffusion of gases, 99.
                               LECTURE III.

Heat  is the key to good ventilation, 101 ;  Heating by radiation,  conduction, and
    convection, 101;  The particles of air too far apart to obstruct the rays of heat,
    102; Radiation of light similar to that of heat, 103 ; Air is heated by immedi-
    ate contact with a hotter body, 104 ; The sun's rays 180° in a snow-bank, 104 ;
    Convected heat the great curse of the American people, 105 ;  Should breathe
    cold air and be warmed by radiant heat, 106 ;  Uneven temperature heated by
    the open fire, 107 ;  Cold feet and hot heads, 107 ; We must either change our
    manner of sitting or heating, 107 ;  Abuse of direct radiation without air supply,
    108; Losses  of animal  heat  by radiation to a cold window, 109;  Never sit
    with the back to a window,  110;  Improved method of heating by a combina-
    tion of direct radiation and  currents  of partially warmed air with the heating
    surfaces placed under the cold windows, 110.
                               LECTURE IV.

General want of interest  in  ventilation, 112; Never have  thought about it,-112-
    Great mortality among children,  112 ;  Smothered  to death by foul air  112 •
    Millions spent to destroy each other but not one dollar to analyze the poisonous
    air that killed more than war, 113 ; Medical colleges do not teach the analysis
    of air, 113;  Examination of public and private buildings, 114; The Capitol at
    Washington, 114;  The dissatisfaction owing  to improper heating, 114 •  Filled
    with over-heated air, 115; No radiation, 115; The direct rays of the sun  the
    great disinfecting and purifying power, 115; Experiments tried, '67 and '68,115 •
    Ventilating into a loft very bad, 116; Wounded man begged to be moved from
    Hall of Representatives to porch to get fresh air, 119; Suggestive modifications
    120; Foul air taken from top and bottom, 120 ; Air in passages to be kept pure'
    120; Floors warmed, and all solid  bodies, 120;  And cool air introduced  for
    breathing, 123;  Being cooler would fall, 123; Firemen 'do not take  cold in  the
    fire-room of ships, 123; Heated shafts instead of fans, 124 ; Certificates of  the
    leading architects, 124; Treasury building, 127;  Had  open fires in old part
    127; Less sickness, 127 ;  South and West wing heated by warm-air currents'
    128; I originally advocated this system; have learned  better, 128-  Fresh-air
    duct overflowed by sewer, 130;  CeUars ventilated  into the hot-air chambers
    133; Excessive  absentees on account  of sickness,  133; "Treasury poison " 
Contents.
11
    common  term among the doctors, 134;  This is not an exceptional case, 134 ;
    Most hotels  and large buildings very similar, 134 ;  Improvements introduced
    into North Wing, 137;  Philadelphia  Ledger building, 137;  No ventilation,
    138;  Hospitals and asylums, 188; Dr. Smith reports problem  of ventilation
    not yet solved, 139;  Marine Hospital,  Philadelphia, 139; General  arrange-
    ment  objected  to,  139 ; Visit to hospital  operation not  satisfactory, 140,
    Asylum for Blind, Columbus, Ohio, 142 ; Ventilated by heated shafts well dis-
    tributed,  142 ; Heated by warmed air currents and radiation, 144 ; Church, Falls
    of Schuylkill, 145; An architect wanted that could design chimneys and venti-
    lators for an American church, 146 ; Friends' meeting-house not ventilated cor-
    rectly, 147 ;  Heating badly arranged,  147;   St. Ann's Church, Brooklyn, well
    heated and ventilated, 151;  But not so perfect as to obviate the necessity of
    some attention, 155; Simple method of heating all buildings more pleasantly, 155;
    Plans for modifying the flues at Westtown boarding-school, 156;  Bad sanitary
    arrangement, 158; Too much shade around this building, 159 ; Juvenile Asylum,
    Washington Heights, New York, 159 ; Public schools, Philadelphia, 159; Funda-
    mental principles of sanitary science set at defiance in a reckless manner, 161;
    How long shall the plea of ignorance be sufficient justification for these murder-
    ous arrangements ? 161;  Suggestions for a school-house well sunned and aired,
    162; Green  blinds should be used instead of curtains, 162;  Philadelphia cot-
    tages, 164 ; General construction excellent in a sanitary point of view, 164; De-
    scription  of New York tenement houses, 165 ; Very unwholesome, 165;  Section
    of a tenement house, 166 ; Difficulty of good ventilation in  them, 167; Phila-
    delphians fail to make a good use of their advantages, 167; Consumption certain
    m'Ucation of filthy habits, 167; View  of Paris,  showing many chimneys, 168;
    The use of stoves advocated, 169;  View of old-fashioned house, showing more
    ventilation than a whole  block of modern houses, 169.


       THE GRAND PRIZE AWARDED  AT THE PARIS EXHIBITION.
The Prize awarded to Dr. Evans, 171;  Ventilation the first sanitary want  in New
    York and Brooklyn, 171; Plan for hospital, 172;  Arrangements made for the
    escape of foul air from level of  floor in winter,  174;  Some  direct radiation
    needed in every hospital, 174;  Superiority of light airy buildings over dark air-
    tight structures, 175.


THE  VENTILATION AND  WARMING OF THE MUNICIPAL  HALL, PITTS-
                                BURGH,  PA.
City Hall, Pittsburgh, 177 ; Comparative value of the heated shaft and fan for ven-
    tilation, 177; All the  heating  surfaces placed  on the outside, 178;  Separate
    ventilators must be provided for the water-closets, boiler-room, &c, &c, 181;
    Advantages gained by the use of these shafts, 181;  Computation for ventilating
    the building, 182;  Result  compared with  Capitol at Washington, 182;  The
    heated shaft ten times as valuable as the fan, 184; The heat should be applied
    at the bottom of the shaft and  not at top, 184;  Common errors in obtaining
    air for ventilation, 185;  Ventilating shafts should be near water-closets, 186 ;
    Fresh air to be secured, 187;   Heating surface so distributed  as to- cause
    uniform temperature throughout the building, 188. 
12
Contents.
                           CAST-IRON STOVES.
The cast-iron stove in disgrace, 189 ;  Quotations of different writers, 189 ; The stove
    more valuable to us than the gold-mines of California and Nevada, 190;  Grave
    importance of  the  question as to obtaining  the best conditions of the  public
    health, 190 ; One great fundamental condition of our existence is to maintain a
    uniform temperature of the body, 190 ; Open fires of wood and coal too expen-
    sive for general use, 191;  Want of a good supply of fresh air one cause of the
    outcry against the stove, 191; The  Franklin stove, 192; The different ways of
    heating, 193 ; Our  belief that hundreds and thousands die every year from the
    escape of carbonic oxide through badly constructed flues, 194;  Illustration of
    this fact, 194;  Suggestions to the French Academy of Sciences, 198.

                         VENTILATION—COOLING.
Description of a city dwelling from the Manufacturer and Builder, 199 ;  Discomfort
    of heat and smells from the kitchen, 199 ; Let the kitchen have a large venti-
    lator of its own, 200; Advantages of shaft from kitchen, 200; Plan of pri-
    vate  dwelling,  201;  May be used for cooling the house in  summer, 202;
    Building a fire in the range, 203; The general ventilation  of the house good,
    204;  Equitable Life  Assurance Society,  205; Dwelling-house  in the country,
    210;  List of buildings for which plans for ventilation have been given, 213;
    Letters from eminent sanitarians, 215. 
                 FIRST   COURSE,

DELIVERED BEFORE THE FRANK LIN INSTITUTE,

               DURING  THE  WINTER  OF 1866-67.
                           LECTURE I.

   Philadelphia is one of the healthiest cities in the United States,
 and, in proportion to the number of its inhabitants, few more healthy
 cities exist in the world.
   This is not owing especially to  its more salubrious situation, but
 should be attributed, in a great measure, to the accidental superiority
 of the ventilation of a large proportion of its dwelling-houses.
   Notwithstanding this comparative excellence, the theory of ventila-
 tion is not so thoroughly understood, nor is the practice so perfect,
 even in this city, that  no advantage can be gained by further know-
 ledge upon the  subject.
   Far from it. From the very best information we can command, and
 with the  most accurate statistics at our disposal, we are forced to the
 conclusion that about forty per cent, of all the  deaths that are con-
 stantly occurring are due to the influence of foul air.
   The Registrar of Records of New York gives nearly half the deaths
 in that city as resulting from this cause.
   The deaths in this city for 1865, according  to the report  of the
 Board of Health, were seventeen thousand one  hundred and sixty-
 nine ; the average age of those who  died was between twenty-three and
 twenty-four years. It ought to have been twice that, as shown by some
 districts in the city and also in the country, where the houses are so
 arranged that they frequently have good ventilation.
   Taking the deaths caused  by foul air at a very low  estimate, say
 forty per cent, of the whole, (the per centage from that cause is not
 so great  as in New York,) we have six  thousand eight  hundred and
 sixty-eight deaths in this city, caused alone by impure air, in one year.
   It is estimated by physicians that there are from twenty-five to thirty
 days of sickness to every death occurring; there would therefore be
something like two hundred thousand days of sickness annually as an
effect of foul  air.
   We all know how very expensive  sickness is, but few persons realize 
14              Rijtense of Unnecessary Sickness.

the enormous aggregate expense of unnecessary sickness in a city like
Philadelphia.*
  This subject has awakened much  interest in Europe of late years,
and has led to the expenditure of immense sums of money, for the pur-
pose of improving the sanitary condition  of its cities.
  Dr. Hutchinson estimated the loss to the city of  London, growing
out of preventable deaths and sickness, at twenty millions of dollars
annually, and Mr. Mansfield estimates the loss from this  cause to the
United Kingdom at two hundred and fifty millions of dollars.
  In the single State of Massachusetts, an estimate exhibits an annual
loss of over sixty millions of dollars by the premature death of persons
over fifteen years of age.
  It is estimated that a few only of the principal items of expense in-
curred by preventable sickness  in the city of New York  amount' to
over five millions of dollars annually.
  And if it is thought that Philadelphia is exempt from such enormous
unnecessary expense,  just glance at  the report of the Board of Health
for last year, and see  how the deaths from disease of the lungs largely
exceed those from any other disease.
  Consumption is almost entirely the result of breathing impure air,—
it is as preventable by the exclusive use of pure air as maniaa potuor
drunkenness is by the exclusive use  of pure water. And see, too, what
slaughter among the innocents—over twenty-five per cent,  of the whole
deaths were under one year of age.
  The infantile mortality is by many considered the most delicate
sanitary test.  But  why does such  an  intelligent community as  this
bo neglect its own interest?
  They have listened to and satisfied the first imperative, demands of
nature—shelter from the elements and warmth,.—and in doing this they
have not brought into use that  much higher order of intellect which
can alone teach  them how to supply, in connection with an agreeable
warmth, an abundance of pure  air in their otherwise air-tight houses.
  I have been much interested in examining a large collection of tables
of the analysis  of air,  which accompany a report to Congress, on
" Warming and Ventilating the Capitol,"  prepared by  Thomas  U.
Walter, Professor Henry and Dr. Wetherill. These  tables were made
by men of various nations, giving the results of their analysis of air
  * I mean merely pecuniarily—in dollars and cents;—the cost in physical
mental anxiety, of course, cannot be computed in dollars and cents. 
Table of the Analysis of Air.
15
taken from all manner of places, from great elevations on the moun-
tains and  in balloons, from the valleys, from the centre of the ocean,
and from the middle of the continent,  in cities and in the country, in
winter and in summer, at night and in the day, and also the compara-
tive analysis of the air out of doors and in  houses.   Believing that
these would be of much interest and assistance to us  in the investiga-
tion of the subject under consideration, I  have  had copies made of
some of the most interesting.
  These give the per centage of carbonic acid in the air as the test of
the amount of impurities in it.
  This is  not an infallible test by any means—there  are various other
causes of  deterioration.  There is the exhaustion of the oxygen con-
stantly occurring to support combustion and animal life ; there are
various other deleterious products of combustion and respiration be-
sides carbonic acid.  But, as carbonic acid is always found in certain
known proportions in pure air, and is always formed  in certain known
quantities  by respiration or combustion, it is considered by many to
give a very fair indication of the condition of  the  atmosphere with
reference  to its influence on animal life or combustion.
  I think one of the most valuable lessons to be learned by the study
of these tables is the uniform purity of the external  atmosphere all
over the world, even in large cities.
  This is  strikingly illustrated in the case of the analysis of  the air
in the city of Manchester.
  We have nothing in this country like that city, where two millions
of tons of coal are burned annually, the smoke from which fills the air
and stretches like a black cloud far into the country.
  Thus,added to the five hundred tons of carbonic acid  thrown from
the lungs  of its animal life every day, are  many times that amount,
(some two thousand tons,) daily, pouring out from its forest of factory
chimneys.
  To this city were the labors of the "Health of Towns Commission"
first directed, to see if they could not find in the air of its streets that
mysterious influence that has caused such alarm throughout the civil-
ized world, as the thoughtful  and intelligent sanitarian sees one-half
of all his fellow-citizens hurried to untimely graves.
  They were disappointed, and well might Dr. Smith exclaim,  after
the most thorough and careful investigations, "How insignificant are
the works of art in contaminating that vast ocean of air that is con-
stantly sweeping over the surface of the earth!"   But do not be dis- 
16
External Air Generally Pure.
couraged:  more recent investigations have discovered the whereabouts
of this pestilential breath.
   I have placed the table of Dr.  Angus Smith's analysis of the air of
Manchester at the head of the list, and have copied it complete, because
it is the only table that I have examined of the analysis of the air of
towns in Europe or North America, in which there occurs  an amount
of carbonic acid exceeding ten parts in ten thousand.
   Here we see three such cases in the twenty-eight experiments, one
ten, one twelve and one fifteen.
   The average of the whole is also greater than in any other similar
tables, being about  seven and a half parts in ten thousand.   This is
certainly quite a perceptible contamination, pure air containing four
or four and a half parts in  ten thousand.  Yet considerable as this
appears in this view, the additional amount of carbonic acid  is only
the proportion that would be added to the air, if unchanged, of a room
fifteen feet square and ten feet high, by a father, mother  and three
children, with a gas-light, in seven minutes.
   And this, probably, is the  highest average contamination  that is
produced by artificial means upon the air of any city in the world.
   There are, of course, great  natural causes which affect the air of
whole countries, such as the decomposition of  great masses of vege-
table matter similar to that occurring on the low fiat lands along rivers,
especially where they overflow their banks, like the Ohio and Missis-
sippi.  The best system of  ventilation, as applicable  to this kind of
foul air, is to keep as far out of its reach as possible.
   The other tables  giving  the analysis of the air  of  London, Paris,
Madrid, Geneva, Bolton, England, at different elevations on  the moun-
tains, on the Atlantic Ocean, Washington City and various other places,
are interesting  only because they show so great a uniformity in the
carbonic acid, seldom exceeding six parts to the ten thousand, and sel-
dom under four.
  But now let us look upon the other side of the room. Here we have
tables giving the "carbonic acid in houses."  Here we will find very
different results.  But the first is a green-house; in that there is no
trace of carbonic acid in the evening and scarcely a trace in the morn-
ing.  Plants, you know, absorb the carbonic acid, and give off oxygen,
while animals absorb the oxygen and give off carbonic acid, thus keep-
ing up the equilibrium.in nature, as is so beautifully shown in the aqua-
rium. Plants are generally supposed to give off carbonic acid at ni^ht,
but it must be in very small quantities. 
Our own Breath is our Greatest Enemy.         17
  I consider them very conducive to health in a living-room, morally
and physically.
  But thi3 want of carbonic acid does not last Ions'.
  The next is M. Dumas' lecture-room.  At commencement of lecture
42-5,  and at close of lecture 67 parts in ten thousand.
  Now,  I think we are on the right track for discovering that myste-
rious  poison that  has carried so many of our friends to their graves,
even in  the very prime of life.
  Here  we have dormitories, 52; do., 37; asylum, 17; school-room,
30; do., 56;  Chamber of Deputies, 16; Opera Comique, parterre, 15;
do., ceiling, 28;  stable,  7;  do., 14; hospital, Madrid, 30;  do., do.,
43; air  of bed-room on  rising in the morning, 48; the same  after
being ventilated two hours, 16; railroad car,  34; workshop,  Munich,,.
19; full room, do., 22; lecture-room, 32; beer-saloon, 49;  and worst
of all is a well-filled school-room, 72 parts of carbonic acid in 10,000.
  That, I think, is enough.   Here we have the solution of the whole
mystery.
  It is not in the external atmosphere that we must look for the greatest-
impurities, but  it is in  our own houses that  the  blighting, withering;
curse  of foul  air is to be found.   We are thus led  to the conclusion.
that our own  breath is our greatest enemy.
  The "Health of Towns Commission," in their investigations,  after-
examining various trades, where the employees were confined mostly
in houses, and having left the scavengers to the last, expecting to find!
a rich harvest of  mortality among them, were much surprised to find,
them  more healthy than many very clean occupations, but which were
conducted in houses instead of in the open air.  I have not the sta-
tistics before  me,  but I should not be surprised to learn that that sin-
gular  race of beings that live in the sewers of Paris were as healthy,
if not even more  so,  than the operatives of some  of  those exquisitely
beautiful, clean, air-tight factories  of New England.
  There was quite an account made a few years ago of the wonderful
cures  of consumption that had been performed by the patient being;
removed to the stable where he could be in close proximity to the cow,
and I have no doubt  many consumptive patients  would find great-
benefit by such a course of treatment, not that there is any virtue in<
the  smell  of the cow, but that the air of the cow-stable would be nearer
pure than that of their own chamber.
  Many go or send their  families to the country in summer to get fresh
air.   Some go to the sea-side, others to the mountains; but there en-
           2 
18        Unfortunate Prejudices against Alght Air.

sues a greater change in a few minutes in a close bed-room by being
occupied by a family than there is difference between the external air
of any city and that of the country.
   The reason why cities are so much more unhealthy than the country,
is  not because the air in the street is so much more impure, but  be-
cause the houses are so built together that this vast ocean of air can-
not get at and through them to purify them as it does in the houses in
the country, and the reason why Philadelphia is so much more healthy
than its neighbor, New York, is because the houses here are built more
like those of the country, so that the air can sweep all  around them,
and sometimes through them.
   I chercfure believe, that a family living in the  filthiest street in  our
citv, if they were careful to have a constant current of air from that
street, filthy as it was, passing through the house at all times, night
and dry, would be more healthy, other  things  being  equal, than a
family spending their winters  in the finest house, if kept air-tight, in
the hunlthiest location in the city, and their summer in the country,
especially if they were always careful  to exclude the night air from
their bed-rooms.
   I say  "night air;"—there is, unfortunately, an unnecessary preju-
dice against what is termed night air, which means, I suppose, fresh
• external air from the dark.
   To show that this is not a new idea, I will read a few lines from the
writings of  a very accurate reasoner and  an eminently practical  me-
chanic  and philosopher, one whom I consider even now one of the very
best authorities upon the subject of heating and  ventilation.  I mean
ithe illustrious man after whom this Institute was  named, Benjamin
:Franklin.
   In his letter to Dr. Ingenhaus, physician to the Emperor, at Vienna,
'he says: *   *  *  *   "for  some are as  much afraid of fresh air as
persons in the hydrophobia are of fresh water. I myself had formerly
this prejudice—this aerophobia, as I now account  it,—and dreading the
supposed dangerous effects of cool air, I considered it an enemy,  and
closed with  extreme care every crevice in the rooms I inhabited.  Ex-
perience has convinced me of  my error. I now look upon fresh air as
a friend: I even sleep with an open window. I am persuaded that no
common air from without is so unwholesome as  the air within a close
room that has been often breathed and not changed.   Moist air, too,
which I formerly thought pernicious, gives me now no apprehensions;
for considering that no dampness of air  applied to the  outside of mj 
Dr. FranI litis Opinion.
19
skin can be equal to what is applied to and touches it  within, my
whole body being full of moisture, and finding I can lie two hours in
a bath twice a week,  covered  with  water, which  certainly is much
damper than any air  can be, and this  for years together,  without
catching cold, or being in any other  manner disordered  by it, I no
longer dread mere moisture, either in air, or in sheets or shirts; and
I find it of importance to the happiness  of life, the being freed from
vain terrors,  especially of objects that we are every day exposed in-
evitably to meet with.
   "You physicians  have of late happily discovered, after a contrary
opinion had prevailed some-ages, that  fresh and cool air does good to
persons in the small-pox and other fevers.  It is to be hoped,  that in
another century or two we may all find out that it  is not bad even for
people in health.  And as to moist air,  here I am at this present writ-
ing in a ship with  above forty persons, who have had no other but moist
air to breathe for six weeks past; everything  we  touch is damp, and
nothing dries, yet  we are all as healthy as we should be on the mountains
of Switzerland, whose inhabitants are not more so  than those of Ber-
muda or St. Helena, islands on whose rocks the waves are dashed into
millions of particles, which fill the air with damp, but produce no dis-
eases, the moisture being pure, unmixed with the poisonous vapors aris-
ing from putrid marshes and stagnant pools, in which many insects die
and corrupt the water.  These places only, in my opinion, (which, how-
ever,  I submit to yours,) afford unwholesome  air;  and that it is not
the mere water contained  in damp air, but  the  volatile  particles of
corrupted animal matter mixed with that water, which renders such
air pernicious to those who breathe it;  and I imagine it a cause of the
same  kind that renders the air in close rooms, where the  perspirable
matter is breathed over and over again by a number of assembled
people, so hurtful to health.
   "After being in such a situation many people find  themselves affected
by that febricula, which the English alone call a cold, and, perhaps,
from that name,  imagine they have caught the malady by going out
of the room, when it was, in fact, by being in  it."
   Now, to show that his hopes have not yet been fully realized, although
one century has nearly closed since  he wrote  what I have just read,
and this unnecessary and unfortunate prejudice against night air still
prevails extensively, I  will read a few  lines  from  the highest public
medical authority in this city.  It is the instructions of the Board of
Health for  the prevention of cholera for  1866: 
20
Board of Health on JS~i<jht Air.
                   ARTICLE—"ventilation."
  "Your premises, particularly sleeping apartments and cellars, should
be thoroughly ventilated. Ventilation is no less a purifier than water.
  "It cleanses by oxidizing and drying.  Keep your houses open and
your windows hoisted  during the day in good weather, and from ten
o'clock until four in the afternoon, that they may have the full benefit
of sunlight and  free circulation of pure air.  During the remaining
hours of the day,  and  through the night, keep  the  windoios closed.
When the weather is cool or rainy, be sure to keep a fire in the house,
in order to prevent dampness, or in sparsely settled neighborhoods, or
in the suburbs of the city, have a fire in the house the entire season."
  On page 9 we read:  "Be careful to dress comfortably for the season,
avoid the night air as much  as possible, and when thus exposed, put
on an extra garment and do not go into the night air when in & state
of perspiration."
  Thus, while recognizing the great value and importance of ven-
tilation in a general way, they give the most definite instructions for
thoroughly and  most  effectually preventing it, because it is at night,
especially when  we are  asleep and cannot move from the air, that the
air ought to be moved from us.
   The frequent recommendations  to avoid "night air" are simply
recommendations to smother ourselves to death, because the foul, poison-
ous exhalations from our lungs cannot  be removed from our chambers
without being replaced by night air;  there is no other fresh air at night
but night air.
   The recommendation, to build a fire in the house on cool days, and in
low marshy districts every day in the year, is an excellent one.
   The recommendations to dress warmly and to avoid checking a per-
spiration suddenly, are  valuable suggestions and  too much attention
cannot be paid to  them.
  But they are of equally great importance in reference to day  air as
to night air.
  To shelter oneself from the sudden change of temperature after sun-
down is an animal  instinct, and a very necessary one, which is strongly
implanted in man  and beast  alike.
  The harm comes from the fact of so intelligent and  intellectual  a
oody as  the Board of  Health of Philadelphia encouraging the  ac-
complishment of this  very desirable object, by thwarting that  great
universal law of our Creator, the ceaseless agitation of the°air by  which 
Cholera Avoided by Fresh Air Night and Day.
21
Fig. 1.
it purifies itself, (and by which perversion of nature's laws millions are
already being killed unnecessarily every year,) instead of their  en-
couraging its accomplishment in that much more healthy and rational
way by adding more clothing or more  fuel to the  fire, and still con-
tinuing to breathe the pure air at night as well as in the day-time.
  I have practised for many  years  sleeping with my windows open
every night, summer and winter, allowing the unobstructed breeze to
flow across my bed, to the great improvement of my health and strength.
  There is no objection in a well ventilated  room to  having a fire if
desired.  A small room with a hot stove or open fire and the windows
open, is much more wholesome than a large air-tight room freezing cold.
  Let us illustrate this by a simple experiment.  Here we have a very
small tube, in which we place a lighted candle, occupying nearly the
                   entire space—this burns brightly,
                   you see.
                     Here  we  have another glass
                   chamber,  much handsomer  and
                   twenty times as  large;  we  also
                   place a similar candle  in  it,  that
                   burns with equal brightness, but
                   watch  them  both for a few  mo-
                   ments—see how rapidly this light
                   in the large chamber diminishes
                   in sfze.
                     That represents, in a  beautiful  manner,  the
 diminished force of your life in an air-tight  room.   There it  goes—
 entirely extinguished by foul air  in so short a time, but the other
 continues to burn just as brightly as when first lighted.   The  smaller
 one had the window open, so to speak; we will imagine the candle in
 the large chamber to be a consumptive patient who thought the room
 so large he did not need the windows open.   Remember, therefore,
 that no matter h»w small your room is, if there is a constant circula-
 tion of fresh air through it, the lamp of your life  will burn brightly;
 but if ever so large and air-tight, your life will soon be extinguished.
   Instead of  averting the cholera by avoiding fresh air at night, the
 experience of the last summer seems to have taught  us- just the con-
 trary ;  for whilst most physicians admit that they are still unable to
 explain satisfactorily, the cause or  remedy for this most mysterious
 disease, that has within a lifetime  carried its fifty millions of  victims
from  time to eternity, they almost universally believe it is a  foul air
poison, and  they have as yet found no surer prevention than pure air.
jiftiin
 
22       Less Carbonic Acid at Xight than in the Day.

  One of the  most  striking illustrations of this, and perhaps one of
the most wonderful cures of cholera on record, was that of the New
York  Workhouse on Blackwell's Island.  It lasted only nine days,
but in that brief period one hundred  and  twenty-three out of eight
hundred inmates died.   I Visited the building with Dr. Hamilton, on
the third day after  its appearance, but the hospital then  contained
sixty  or  seventy patients, and  some twenty-five or  thirty had died
within twenty-four hours.
  Dr. Hamilton attributed  the rapid propagation and fatality of  the
disease, after  it once  had  gained  admission, mainly to  confinement
and crowding.  It was observed that the  cholera was  confined,  for
several days, among the women; the women had  the smallest apart-
ments, were most  crowded  in  their cells,  and with few exceptions,
were employed within  the building, in close contact with each other
during the day.  The men  were employed mostly in  the quarries and
out of doors.
   The doctor's prescription on  that  occasion  is worth studying.   It
is very short and simple, however.
   A slight  change was made  in the diet; disinfectants were used ;
fifteen drops of the tincture of capsicum with an ounce of whisky, ns
a stimulant  at night, was all  the  medicine given to each individual.
But the great means the doctor relied upon for success, was pure air
all the time.  They were kept out of doors from morning until night,
and all the  windows were kept  open night  and day; and although in
the hot  weather of summer, fire was made  in the  wards, to insure
more perfect ventilation.   In  six  days  after the initiation of these
simple hygienic measures, the epidemic entirely disappeared.
   The disorders and sickness caused  bv the too rapid chillinc of the
unprotected body after sundown, have given rise, I have no doubt, to
that erroneous popular prejudice  so common among all classes, even
those of education and ordinarily good  common  sense, who imagine
there is some peculiar poison or source  of  unhealthiness in the air at
night, that  is not  contained in the  air in  the day-time.  It will no
doubt greatly relieve the minds of these from such "vain terrors."
and prove most conclusively the entire fallacy of such reasoning, to
examine these tables again.  In the copies I have  made, I have not
classified the results given  by  day  and by night, but a careful exami-
nation in detail, fails to show any appreciable difference in the aggre-
gate, by day or by night.
   Mene's numerous experiments on the air  in Paris, gave less carbonic
acid at night than in the day-time. 
Candle  Extinguished in Human Breath.           23
  Lewey's  analysis on  the Atlantic ocean, one thousand miles from
the coast, gave a decided excess in the day over that of the night.
He attributes this  to the action of  the  sunlight upon the ocean
liberating the gases which it holds in solution.
  In  cities there is a much larger quantity given off from burning
coals  of factories in the day-time than at night.
  It is not improbable, however, that  the  more  rapid evaporation of
moisture towards evening may carry with it the volatile  particles  of
corrupted animal and vegetable matter to an extent slightly in excess
of that which occurs in the  morning, but  it is believed these would
not equal  the greater  contamination  from burning  coals,  a/id  the
usually greater stillness of the  air, producing  partial stagnation, so
that the air would be a little nearer pure at night than in the day-time.
And  how  unmistakably do all  these  investigations prove what we
ought to have known and accepted without a moment's hesitation, that
the Creator, who has made such  vast and such  minute provisions for
supplying every living creature with a constant and copious supply of
 fresh air, and has made it so important for their existence that they can-
not live a moment without it, has made the air at night just as pure
and wholesome as in the day-time.
   We have thus traced  the scourge of foul air to our houses, and much
of it  to our bed-rooms.   The next question  is, how to get clear of it.
   We want to know, however, what poisons the air, so as to know in
 what part of the room it is to be found.
   We will try a very simple experiment, to show you  what a deadly
 poison the breath is,—to the flame of a candle, at any rate.
   Here is  a simple glass tube, open at both ends—an  ordinary lamp
chimney—a  candle burns freely as you see, and would  burn  so  all
night, if it did not  burn out.   I will now remove
the candle, and breathe into the tube  through this
pipe, and now you  see how suddenly the candle is
extinguished as I drop  it in again.
   Animals are  killed  suddenly or  after a more
 prolonged struggle, by the exhaled breath, accord-
 ing to the activity or sluggishness with which the
 blood circulates—a  bird  would  be  killed very
 soon_Some partially torpid animals would live a
 long  time.   Man has great endurance—struggles
 Ion"  and hard;  but if  closely  confined, will  be
 poisoned to death in  one night, as in the case of
 those confined in the celebrated Black Hole of Calcutta, and on board of
 
24
The  Breath Falls.
vessels where they have been confined below decks in time of a storm.
Others will struggle on longer, as in the case of the two thousand and
twenty-six who died of consumption last year, in Philadelphia.
  And now let us see in which part of the room  this deadly poison
of our breath  is mostly found.
  It is the popular idea, that because the body, and consequently the
breath, is'warmer  than the  ordinary temperature of a room, it rises
and accumulates at the ceiling.
  Upon this theory most of our buildings have been ventilated whenever
any attention whatever has been given to the subject; but that theory
is incorrect;  consequently, all practice based thereon is also wrong.
  This subject of the direction taken by the breath upon leaving the
body, has been warmly discussed within  a few years.  It has been a
very difficult matter to prove conclusively  and satisfactorily, but I
think we have devised some very simple experiments that will prove
to you very clearly what we have stated.
  I have here a simple glass  tube two feet long  and one and a half
inches interior diameter;  one end is closed with a rubber diaphragm,
                                  through which is passed  a  small
                                  rubber tube—the  other  end  is
                                  all open. We will rest this about
•<^J|                    !     ^-  horizontal,  and taking  a  little
 W^Mnnnms^mmmmmmmm^      smoke in the mouth> it  will be
discharged with the breath into the glass tube; it is first  thrown
towards the top, but it soon falls, and now see it  flowing along the
bottom of the  tube like water—watch it  as  it reaches the far end—
there, see it fall almost like water.
  Now, by raising the closed end of the pipe, you see we can pour it
all out, and by filling it again and raising the other end, it falls back.
  Thus you see that, notwithstanding the extra warmth in the breath,
it is heavier than  the atmosphere, and falls to the floor of an ordi-
nary room like this, say, when the temperature is  from 60° to 70°.
This is owing to the carbonic acid and moisture contained in  it.
  I have varied this experiment in a number of  ways, by passing it
through smaller tubes  and discharging it into the  air in one or two
seconds after  leaving the lungs, and by  passing it  through water of
various temperatures,  and  discharging  it  into  rooms of  different
temperatures,  with  the  same general  results.    As  the tempera-
ture of the air diminishes, the tendency of the  discharged breath to
rise increases.   Much care is required in conducting these experiments,
 
Doctors' Certificates not Explicit.             25
Fix.
to avoid as much as possible, the  local currents which  are  always
present in a room.
   This  is a very important  fact to be  borne in mind; yet notwith-
standing this, there  are times, under certain circumstances, in which
the foul air will be found in excess
at the top of the room.
   For the  further examination of
this subject, we have here a little
glass-house with glass chimneys
and  fire-place in the first  and
second stories.
   As the flame  of a candle is
such a beautiful emblem of human
life, we will remove the roof  and
part of the floor of  the second story, and place four candles in our
house.   They are all  of different  heights, you see.  We will call
them a father, mother and  two children.
   As carbonie acid is that much dreaded poison in our breath, and
the heavy portion of it which causes it to fall to the floor,  we will
make a little  by placing a few scraps of common marble in this glass
vessel, and pouring over  it  some sulphuric acid.
   It is now forming, and will fall and  flow across the floor the same
as carbonic acid does when it pours into a basement from the gutters
 on  the street or filthy yards where it  is formed, and  before it is
 absorbed or diluted by the  current of pure air sweeping over them.
 It first kills the  smallest  child, because it is  nearest the floor.  You
 remember the excessive infantile mortality in  this city in 1865.  This
 is partially owing to their breathing  more  of this foul air near the
 floor, and  partially owing to the  great  fear  of their  mothers and
 nurses, of letting the little  innocents get a breath of  fresh air for fear
  it will give them colic, and consequently they smother them to death.
   The other'child dies  next, and then the mother, and lastly the
 father.
    Thousands are thus poisoned to death by their own breath every year.
  But did you ever  see a physician's certificate that gave you any
 such idea?  Why do not the  doctors tell the living, in such language
 as they can understand, what killed their friends, so they may avoid
 it in th-ir own case, instead of giving  it in some Latin terms which I
 fear many interpret to  mean some "special dispensation of Divine 
26               Fire-places Good  Ventilators.

Providence instead of the true cause—their  utter disregard of the
laws their Creator made  for the preservation of their health ?
  Had this family known enough about  ventilation to have kept the
fire-place  open, with a little fire in it now and then, they would not
have been thus killed.
  Let us see—we will  take  out the  fire-board which has been put in
to make the  room  look  a little neater, and with a very  small  light
there to create a draft in the chimney.
  We will again light the candles, and pour in the poisonous breath.
Ah ! there goes the little one—he is hardly high enough  to keep out
of that deadly current flowing across the floor.
  We shall have  to let it in a little slower,  or we will set him on a
platform,  as  many persons who have  carefully studied this subject,
consider it judicious to do.  Now, by the  smoke from this taper, you
can see the air is flowing across the floor and  up the chimney.
  There has  been a steady current flowing in long  enough to have
filled the house, but the lights are all burning  brightly, and you thus
see  the  value of an  open  fire-place  for  ventilation.   Thousands
of lives are thus saved,  and many more would be if all  fire-places
were kept open.  I have recommended hundreds of  fire-boards to be
cut up  for kindling-wood, as I  consider this is the best use that can
be made of all fire-boards.
  Never stop up a fire-place in  winter or summer, where any  living
being stays night  or day.   It  would be about as absurd to take  a
piece of elegantly tinted court-plaster and stop up the nose, trusting to
the accidental opening and shutting of the mouth for fresh air, because
you thought it spoiled the looks of your face so to have two such great
ugly-looking holes in it, as it is to stop your fire-place with elegantly
tinted paper because you think  it looks better.
  If you are  so fortunate as to have a fire-place in your room, pamt
it when not in use; put a bouquet of fresh flowers in every morning,
if you  please, or do anything to make it attractive; but never close it.
  Now, there  are other conditions in which a fire-place or  an opening
near the floor, will not answer for ventilation.   This occurs in rooms
where the air is made  impure by burning lamps or gas, and where the
fresh air  entering the room is cooler than the  temperature of the
room itself.
  To illustrate this, we will put the roof  on  and take the entire floor
away, or  as  it will be a little more  convenient, we will represent
it by this glass-house,  using this shade for that purpose. 
Ceiling Ventilation Necessary for Artificial Lighting.
  This  is  supported some six inches from  the floor,  and has  no
bottom.   By lighting another candle and standing it  outside, you
can judge  by comparison,  of  the foulness of the
air inside.
   The  tallest  one  is  effected  first,  this  time.
You see that is a perfectly formed light, but it
gives but about half the light  the one does on the
outside; this  is the way with many of us  who are
obliged to, or rather do, breathe foul air half the
time.
  We often  think,  by comparing ourselves  with
others  around us,  that  we are pretty fair specimens of  humanity,
while  really we do  not  give more than half the light  in the world
that we ought to do, and kill ourselves before our work is half done.
  You see the two tallest are dead already, and the others will soon
follow__there they  go.  Here is  the bottom of the  house  removed,
and yet these candles all went out for want, of fresh air.
   Therefore, when we see  the  air is made  impure by burning candles
or gas lights, owing to  its exceeding heat, the foul  air is  mostly at
the top of the room, and especially when  the fresh air  enters cooler
than the air in the room.  We will find, however, that in a very few
minutes the  candles will relight  long before the contained air or  the
glass shade cools down to  the  temperature of the room.
   The products of combustion, like those  of  respiration, are  heavier
 than the ordinary atmosphere, and consequently fall to the floor very
 soon if not removed while very hot,  by special  openings immediately
 over them in the ceiling;  after it has thus fallen, provision must be
 made for its removal from the level of the floor, in connection with
 the foul air from the breath.
    I hope  that by these few simple experiments,  and the statistics pre-
 sented here this evening, we have strengthened your previous convictions
 of the importance of fresh air, because we are well aware that you will
 find, as you  proceed in your investigations of  this subject, that it is
 frequently surrounded with complications; yet the laws governing the
 circulation of air of different temperatures, are as fixed and immovable
 as  the laws  governing the rising and setting of the sun,  and with  a
 very little careful investigation,  can  be easily understood.
   And we  believe no  similar amount  of money or thought,   will
 produce a greater amount of satisfaction  than  the increased health,
 strength and happiness thus secured. 
                          LECTURE II.
   As I stated in our last lecture, much interest is being awakened,
in this country and in  Europe, by recent investigations showing the
enormous numbers of untimely deaths that are caused throughout all
classes of society by foul air.
   It would  have  been a startling announcement, ten  years  ago, to
have  stated  that impure air  caused as many deaths,  and as much
sickness, as all other causes combined, and yet the most diligent and
accurate investigations are rapidly approaching that conclusion.
   Few really comprehend the immense pecuniary loss, to say nothing
of the amount of  suffering, that we endure by this extra and easily
preventible amount of sickness.
   I propose, this evening, to enter upon the consideration of  one of
the most important parts of our subject—the effect produced by heat
upon the movements of air.
   I think it probable that many of us do not comprehend the actual
reality of the air.
  We are apt to say of a room that has no carpet and furniture in it,
that it has nothing in it, while, if it is full of air, it has a great  deal
in it.
   A room between twenty-seven and twenty-eight feet square  con-
tains one ton of air—a real ton, just as heavy as a ton of coal. Now,
there  is not only twenty-seven  feet, but more than  twenty-seven
miles of air piled  on top of us.  The pressure of  the atmosphere at
the level of the ocean is about fifteen pounds to the square inch.   An
ordinary sized man sustains a pressure of about fifteen  tons, and
were it not that this pressure is equal in all directions, we would be
crushed thereby.
   We must accustom our minds, therefore, to consider air a real sub-
stance, and  that it  is as totally  unable to move itself,  or to  be
moved,  without power, as water  or coal.   It requires just as much
power to move a  ton of  air from the cellar to  the second story  as
it does a ton  of coal.
   Heat is the great moving power  of air.   Those whose  attention
has not been especially directed to the subject of the amount of power
exerted by the sun's rays upon the  earth, have  little  conception of
its magnitude.
   The power of all the horses in  the world, added to the power of all
the locomotives, and  of all the immense steam  engines  in all the 
The Sun's Pays the Great Moving Power,
29
world, express but a small fraction of the power exerted by the sun's
rays upon the earth.  It is estimated to be sufficient to boil five cubic
miles of ice-cold water every minute.
   His rays are the chosen power of the Creator for moving all matter
upon the globe.  It is his rays that lie buried in the  vast coal fields
beneath the earth.  His  rays cause every spear of  grass to grow,
rear  the mighty oak, form the rose, burst its beautiful buds, and
send its perfume through the air.
   No bird warbles  its  sweet music in the  air, no insect breathes, save
by his power, and all animals love to bask in the genial glow of his
light and heat.  He rolls the scorching air of  the tropics to frozen
lands, and wafts the ships across the seas.  He forces the heated waters
of the equator to  the poles, tempering all the earth.  He lifts the
water from the sea to sprinkle all the land and cap the distant moun-
tains with eternal snow.
   Now, let us  examine a little more minutely how this influence  is
exerted upon the air, which is the subject  we are especially interested
in at present.
   Does it commence at the top, and heat it,  layer by layer, until it
reaches the  bottom?  Not at  all; but it passes  through the whole
forty-five miles of air,  heating it very little, if any, and falls upon the
solid substances at  the earth's surface, heating them, which, in turn,
heat the air b}T its individual particles coming into immediate contact
with those solid hotter substances.
   We will endeavor to illustrate this in a crude way.
                              Fig. 7.
7///////,/\
  .....~W7777r7^^777777~7777^77'7^ 77^,77/A '  '///
  Here we have a tin tube, a, fifteen feet long and ten inches in di-
ameter- open at both ends; two feet from one end we introduce this 
30          Air not  Warmed by the Pays of Heat.

ascending pipe, 6,  the  upper end of which is merely inserted in a
small flue, extending to the top of the building.  The height of this
flue is sufficient to make a current of air pass through  this tube,  as
you will see by holding this smoking taper at  the far end.  We will
now  place a large heated ball,  <J, at this  end, and outside  of that we
will place this reflector, d, pressing it quite close to the end  of the
tube, so that no air can enter here.
  The rays of heat from this ball, or from any other warm body, are
thrown like  rays of light, in every direction equally; there  would,
therefore, be some  of the rays thrown through this tube to the other
end without any reflector, but  the proportion that would  reach the
other end would, of course,  be  small.
  We therefore collect those going the other way,  and change their
course, and then send them straight through the tube to the far end.
  We will place another reflector, e, at the far  end, to receive and
concentrate those rays, in the  focus of which  we  will place a candle,
f with a little phosphorus on it, to show you that  the rays of heat
are passing through.
  There you see the candle is lighted, thus proving that there is a
strong current of  radiant  heat  coming from the hot  ball, through
the tube to this end.   And you see by this smoke that  there is a cur-
rent of air passing the other way.
  Now, we want to know how  much that air is "heated in passing the
whole length of this tube  against that shower of radiant heat, or
whether  air absorbs radiant heat at all;  but, before going to the other
end, where the hot ball is, we  will take two thermometers that have
been lying here, side by side, both indicating a temperature of 69°.
One of them, g, we will hang at this end, about opposite to the centre
of our tube, which, I think, will give us a fair  average of the entering
air,  first removing, however, the  candle  that has been lighted, and
the reflector.
  We will hang the other thermometer in the ascending tube, at the
end  near the heated ball.  We have had two  glasses, h, inserted
here, so  that we might observe what was going on within.   By the
smoke from this taper you see there is  a strong current of air pass-
ing  up  the tube, all of which must come from the far end, flowing
against the  strong current of radiant heat going in the opposite direc-
tion. NowT, leaving this thermometer to rise or fall according to the
temperature of the air flowing through, we will go to the other end and
examine another very interesting part of this experiment: it is the 
Different Ways of Distributing Heat.          31
manner in which the radiant heat is received and  appropriated  by
different substances.
  Radiant heat is thrown from a hot body in every direction equally,
but no two kinds of substances receive those rays of heat in the same
manner, nor do they make the same use of them after they have  re-
ceived them.
  Every substance  receiving heat, however,  must give a strict  ac-
count of it.   It must give out an equal amount of  heat, or, what is
taken as an equivalent, some action or power.
  I have a sheet of ordinary tin, and as I hold this polished side be-
hind this light, you see it throws a belt of light across the room; and
as I put it  in  front of the end  of our tube, and turn it so that the
rays of heat will be reflected in your faces, I think  some of you will
be able to feel the reflected heat.  The rays of heat are turned from
their course, and thrown in a belt across  the room, similar to the rays
of light.
   But you cannot give away and keep the same thing.   This bright
polished surface appropriates but a very  small portion of the radiant
heat.  A thermometer hanging  for some minutes against the back
has  scarcely risen one degree ;  but we have given  the other  side a
coating of lamp black, with  a little varnish, and by  turning  that side
towards the pipe, the result will  be quite different.   By this coat of
olack varnish the whole character of the sheet of tin is changed.
The black, however, has but little to do with it; if it were white, or
red, or blue,  the formation of the surface being similar in every  re-
spect, the result would be the same almost precisel\\
   Instead of acting merely as a  guide-post, to change the direction
only of the rays of heat, as  before, it now becomes a receiving depot,
absorbing nearly all the heat that comes  to it.   It must soon become
filled, however.  The thermometer hanging at the back has risen  six
degrees already, and is going up rapidly; it must soon begin to dis-
tribute its extra stores.  But  mark the different manner of distri-
buting the heat.  Instead of reflecting  the whole all in one direction,
as when received on the other side, it  now radiates  them equally in
every direction.
   Some solid substances allow the  rays, both of heat and  light, to
pass  directly through them without either reflecting or absorbing
them.  Other substances allow the rays of light to pass through them,
but absorb much of the radiant heat, like clear glass.
   Rock salt is one of the best non-absorbents of radiant heat, allow-
ing nearly the whole of the rays of heat to pass through unobstructed. 
32             Moisture great Absorber of Heat.

  We will now return to our experiment at the other end of the tube.
I find there is  something  wrong here—the mercury in the ther-
mometer has risen  several degrees.   I  knew this was rather a  crude
arrangement for illustrating this very beautiful and interesting part
of our subject, but  I hoped it would assist me a little in conveying to
you the  idea I desired to impress upon your minds.  I find, however,
that it is scarcely delicate enough to illustrate perfectly what I wanted
to show.
  But this increased temperature is not owing to the effect of radiant
heat on  the  air coming from the far end, for I find by the heat at the
top of the pipe, between the heated ball and this ascending pipe, b,
and by the current of heated air on the side next the ball, that there
is a current  of circulating air that has been  heated  by coming into
immediate contact  with the  hot ball.
  I designed this smaller tube,  k, to carry off the air thus heated, but it
appears to be too small.
  We ought to have had a  piece of rock-salt to have closed the end
of this  tube, so that  the radiant heat would  have  passed through
without allowing any circulation of heated air, but I  was unable to
find such a  piece.   But Professor Tyndall, in his lectures before the
Royal Institute of Great Britain, gives the results of a large number
of very accurate and beautiful experiments tried for the purpose of
determining whether the forty-five miles of atmosphere surrounding
the earth absorbed any of the sun's rays, and if so, how much ?
  These experiments prove, in the most conclusive manner, that dry
pure air is almost a perfect non-absorbent of radiant heat.   Thus, were
the air entirely dry and  pure,  the whole forty-five miles through
which the sun's rays have to pass, would absorb a very small fraction
thereof, so that in the  length of our tube it would be but an exceed-
ingly small  fraction of one  degree, that is, for pure dry air.
   But is the air of this room pure and dry ?  Very far from it.
  Professor Tyndall found  that  the moisture  alone in the air of an
ordinary room, absorbed from fifty to  seventy  times  as much  of the
radiant heat as the air does.  Air and the elementary gases—oxygen,
hydrogen and nitrogen—have  no power of absorbing radiant heat, but
the compound gases have a very different effect; for instance, olifiant
gas absorbs 7950  times as  much as air; ammonia, 7260;  sulphurous
acid, 8800 times.  Perfumes, also, have a wonderful power of absorb-
ing radiant  heat.
   The  moisture  in the air,  however, is of the greatest practical 
Furnace-heated Houses very Dry.
33
importance in various ways.   It  is the great governor or regulator
or conservator  of heat;  it absorbs it  and  carries it from point  to
point and into places where the direct rays of the sun could not get;
it is  like a soft invisible blanket constantly wrapped around us, which
protects us from too sudden heating or too sudden cooling.
  Professor Tyndall, speaking of the moisture in the air, says: "Re-
garding the earth as a source of heat,  no doubt at least ten per cent.
of its heat is intercepted within ten feet  of its surface."   He  also
says: "The  removal for a single summer's night of the aqueous
vapor from the atmosphere which covers England, would be attended
by the destruction of every plant which a freezing temperature could
kill.
   "In  Sahara, where  the soil is fire and the wind is flame, the re-
frigeration is painful to bear."
   And in many of our furnace-heated houses, we have an atmosphere
very similar in point of  dryness to that of Sahara, but more impure.
   The foregoing  remarks in  regard to the impossibility of heating
air,  apply especially to radiant heat.   Air does become heated, but
in a  different manner ;  it is heated by each individual particle or atom
coming in immediate contact with some hotter substance.   See what
a wonderful provision for creating  a constant circulation of the air.
The sun's rays pass through it without heating it, but they heat the
surface of the earth at the very bottom  of the ocean of air ;  this, in  its
turn, heats the air by each individual atom coming in immediate con-
 tact with these hotter substances, expanding them so that they must
 rise, thus enabling  the  colder and heavier particles to rush in and
 take their places.  With this great universal moving cause, in con-
 nection with  the innumerable minor  causes resulting from the very
 different absorbing, radiating and reflecting powers of various sub-
 stances, it becomes almost impossible for the air to be entirely and
 absolutely at rest, even in the most minute crack or cranny, or bottle
 corked air-tight.
   Now, to apply these principles to every-day life, to the heating and
 ventilation of our houses, taking the open fire first, we find that it acts
 like the  sun, heating  exclusively by direct radiation.  The rays of
 heat fall upon  the sides  of the room,  the floor and ceiling, and the
 solid substances in the room, which thus become partially heated, and
 in their turn become secondary radiators.   This  radiant  heat  from
 the  fire does not  heat the air in the room at all, but the air becomes
 partially warmed by coming  in immediate  contact with the sides of
the  room, the furniture,  &c.
            3 
 34    An Open Fire the most Wholesome Artificial Heat.

   One  great reason, therefore, why an  open fire is  so much more
 wholesome than any other means of artificial heating, is because it
 more nearly imitates the action of the sun.
   The  rays  of heat fall upon  our  bodies, heating them, while it
 leaves  the air cool,  concentrated and  invigorating  for  breathing.
 The bright glow of an  open fire has  a very cheering and animating
 effect.  It produces a very agreeable  and healihy excitement.
   It is  not improbable that future careful investigations may prove
 that there is an important change takes place in the electric or ozonic
 condition of air as it passes over, or in contact with,  hot iron,  which
 does not occur to the air of a room heated by the open fire.
   The air in a room heated by an open fire can scarcely become stag-
 nant, because  that fire must necessarily be constantly drawing a con-
 siderable amount of air from the room  to  support  combustion, the
 place of which will be supplied by other air, and here is where one
 of the greatest inconveniences arises in  the use of the  open fire; if
 the air  entering to supply this exhaustion comes  in at a crack of the
 door  or window, on the  opposite side of the room, and that air is
 cold, say 10° or 15° above zero, it flows across the  floor to the fire,
 chilling the feet and backs of those sitting in its track.  It is quite
 possible to roast a goose or round of beef in front of  a fire, while the
 air flowing by it into the fire is freezing  cold.  This should be  reme-
 died by having the air flowing in partially warmed before it enters,
 say to a temperature of 40°  to 50°, either by having the halls over-
 flowed by partially warmed  air, and  opening a  door into it,  or by
 admitting the air to enter around the back of the fire-place,  as Dr.
 Franklin arranged it.
   Thus, while an open fire is the healthiest known means of heating
 a  small  room,  and should be in  the family sitting-room of  every
 house, and in offices and other  places  where the occupants are at
 liberty to move closer  or  further from the fire at pleasure,  yet it is
 entirely unsuitable for a  large building, or for rooms  where  many
 persons are  assembled, and  have fixed seats, similar  to a school,
 lecture-room, factory, &c.
  A stove in a room heats both by direct radiation  and by heating
 the air that comes in immediate contact with it.
  But our latest styles of  elegant new patent gas-consuming air-tight
 stoves, require so small an amount of  air to support combustion, that
 there is a strong probability of the occupants of a room thus heated
smothering to death for want of fresh air, sooner or later, and  gene-
rally -the former. 
                 A Store Good for Small Pooms.              35

   But a stove, if properly used, creates a comfortable and wholesome
 atmosphere, and is one of the most economical means of heating now
 known.   There should always be a separate pipe for introducing the
 fresh air from the external atmosphere, which fresh and cold air should
 be discharged on or near,the top of the stove.  And if this supply of
 fresh air is abundant, with a constant evaporation of moisture suffi-
 cient  to compensate for the increased capacity therefor due  to  the
 additional heat  given it,  and  an opening into a heated flue near the
 ceiling, to be opened in the evening  when the gas-lights are burning,
 or when the room is too  hot, and kept shut  at all  other times, with
 another opening into a heated flue on a level with the  floor, which
 should be kept always open to carry off the cold, heavy foul air from
 the floor—a stove thus arranged for many small isolated rooms, makes
 one of the most economical as well as most comfortable and wholesome
 means of heating at our command. It combines the three great essen-
 tials necessary for comfort and health—warmth, partially by direct
 radiation, fresh air and moisture. But  neither the open fire nor the
 stove, as desirable as they may be in many small rooms,  are suitable
 for large rooms, especially where many persons are assembled.  Heat-
 ing principally by circulating warmed air, or in combination with direct
 radiation from exposed pipes filled with steam or hot water, is in such
 cases more convenient.
   It is in connection with this system  of heating by circulating warm
 air,  that the erroneous views in relation  to ventilation generally  en-
 tertained by the public, produce the most injurious effects.
   The special points to be borne in mind in considering  this subject
 are that, when in motion, warmer air rises and colder air falls; but
 when at rest,  the stratums of air of  different temperatures  arrange
 themselves  horizontally.
   One other thing: we must remember temperature has nothing to do
 with the purity or impurity of the air.  The pure air entering a room
 is sometimes colder than the average temperature of the room, and
 falls to the  floor, forcing the warmer, and, in that case, fouler  air to
 the upper part of the room.
   But frequently, in winter, the fresh air enters warmer  than  the
 average temperature of the room, and  rises to the ceiling, and flows
across the room above the colder and fouler air that has been longer
in the room.  You must not forget the experiments in our first lec-
ture, showing that the breath in an ordinary room, of a temperature
of 70°, fell to the floor instead of rising  to the ceiling.  I  propo30 
36             Incorrect Theories of Ventilation.

illustrating  this  part  of our subject, by  using*a little glass room
to show the movements of  air of different temperatures.  We  can
either use air of different temperatures, showing the motion of the va-
rious currents by a little smoke; or, as the laws governing the circu-
lation of liquids of different densities are so similar, and by the use
of a little coloring,matter will express to an  audience of this kind
more promptly  and clearly the ideas which we wish to convey, we
therefore propose using the  different colored liquids this evening.
  The  colors, of  course, have nothing to do with  the densities,  but
are merely used as a convenient method of designation ; the red repre-
senting heat or rarity, and blue, coldness or density.
  The  room is now filled with clear water,  slightly blue, to represent
cold, and  a little salt, which makes it a little more dense than fresh
water.   Now, I will let in at  the top a little fresh water, colored red by
cochineal, to represent heat, and by making a similar opening on the
opposite side for its escape, you will be able readily to see in what direc-
tion it moves.   There, see it entering—see how it flows directly across
the top  of the room, and escapes at the opening on the opposite side.
You see it disturbs the lower and colder parts of the room but very little.
Thus a  large flow of pure fresh warm air might be going through  a
room all day, and be entirely wasted, neither warming nor ventilating
it.  Fortunately, there are  but few  buildings  arranged in quite so
absurd  a  manner as this.   I believe it was tried in the House of
Lords,   on the erection  of  the new Houses  of Parliament, but, of
course,  failed.   I  think they  still  adhere  to  it in  some of  the
wards of some Insane Asylums, where they depend, I suppose, upon
the excitement of the patients to keep themselves warm and the air
stirred up.  I also noticed this arrangement in a new building just
being finished, a few years since, at Yale College.   The architects of
that  building had probably been impressed with the dreadful effects
upon the health of students  of the air from our ordinary hot air fur-
naces, and thought they would avoid all such danger.  I think, how-
ever, it  would have  answered their  purpose just as well, and been
much more economical,  to have placed the furnaces at the coal mines,
and saved the trouble and expense of carrying the coal so far.   I
expect  they have made other arrangements,  probably, by this time.
  We will now close the opening at the top for the inlet of the fresh
warmed air, and open a valve, so as to allow it to flow in at the bot-
tom.  We will allow the opening at the top for the outlet of the foul(?)
air to  remain as before, (see Fig. 2,  Lithograph plates.)   This is 
Fig. I
 
 
Dr. Franlditis Views Correct.
39
quite an improvement; it agitates the air much more than the other,
and by going and standing directly over the register, you can alwaya
get in the current of fresh warm air.  But you see to what a  very
small portion of the room the heated  air  is confined, rising in one
perpendicular column directly to the ceiling, and then flowing  hori-
zontally along the ceiling to the outlet.   How little it disturbs the
main portions of the room, especially the lower and occupied part.
   I hope you will notice that this illustrates the popular  notions of
ventilation.  I suppose three-fourths of all  the buildings in this coun-
try, or  in Europe, where any attempts at  artificial ventilation  have
been made, are thus arranged.  Dr. Franklin knew better, and made
a much more perfect arrangement than this.  But we are probably
mostly  indebted to that very able and  enthusiastic advocate  of venti-
lation, Dr. Reid, for this popular  opinion.  The whoie of the  plan
that he advocated  is but little understood by the public. He assumed
that the natural warmth of the body created an ascending current
around us, and caused the breath to  rise towards the ceiling, and
consequently, in all artificial arrangements, it was best to endeavor
to imitate this natural movement of the  air.  And to overcome the
great practical difficulty we see here exhibited, of the fresh warm air
flowing through the room, and disturbing so  small a portion of it, he
proposed making the whole floor one register, and  thus have an as-
cending column over the entire room.  For this purpose, the floors in
the Houses of Parliament were perforated by hundreds of thousands of
gimlet  holes, and the whole cellar made a hot air chamber.  This was
a  magnificent idea, and, I believe, in some  few instances, where fully
carried out, has given a good degree of satisfaction; but it is always
difficult to adjust the opening and the  pressure so as to cause an even
flow over so large a surface, and at the same time to be so gentle as
not  to be offensive to those  with whom it comes in contact.  But this
thorough diffusion cannot be conveniently  applied in one case  in a
thousand.   It must necessarily be always very extravagant, as it will
constantly require a great amount of air  to insure a thorough circula-
tion through all parts of the room.  I  wish, therefore, most emphati-
cally, to condemn all systems relying upon openings in the ceiling for the
escape  of the foul air,while depending upon the circulation of warmed
air for  obtaining the necessary additional warmth.  In practice they
are  universally  closed in winter* for  the purpose of keeping warm,
and as  such openings have been so generally considered theonly ones
necessary  for the proper ventilation of a room, and as they had to be
                      * See Fig. 3, lithograph  plate. 
 40           When Ventilation from Floor is Best.

 shut in winter, just when artificial ventilation was most necessary, it
 has created a very strong prejudice in the popular mind against all
 ventilation..
   The result of the advocacy of  these impracticable theories by so
 many able and learned men, (most physicians writing upon this  sub-
 ject have adopted them,) has been the shutting up of  many thousands
 and tens of thousands, till they have smothered to death.
   The ravages of consumption and the excessive  infantile mortality,
 and the many diseases resulting from foul air poisons, are in a great
 measure due to  the general advocacy  of these false theories.  As I
 have before  said, Dr.  Franklin knew better than this, and had we
 been contented to have followed his simple practical advice, instead
 of being dazzled by the splendid theories of others, thousands of our
 friends would now be  with  us who died long since for the want of
 fresh air.
   Now, let us see how Dr. Franklin says a room  ought to be venti-
 lated.  He says, " the fresh air entering, becoming warmed and  spe-
 cifically lighter, is forced out into the rooms, rises by the mantel-piece
 to the ceiling, and spreads all over the top of the room, whence, being
 crowded down gradually by the stream of newly warmed air that fol-
 lows  and rises  above  it, the whole room becomes in  a  short time
 equally warmed."  This is the principle upon which his celebrated
 Franklin stove was arranged.   Now, let us see if we can arrange our
 little glass house so as to  illustrate this.   We will first  fill it with
what we call  our cold air, and will close the outlet at the top,  and
take out the fire-board (Fig. 4, lith. plate).  You see the  warm fresh air
 rises immediately to the top, as before, and flows  across the ceiling,
 but as it cannot  escape there, it forces the cold air down, and causes
 it to flow out at  the fire-place.  See how quickly the whole room is
 filled with the fresh warmed air.   Ah ! I see I am a little too fast-
 there appears to be a  stratum of a foot or two, lying on  the floor,
that is not disturbed yet.   It  flows out at  the top of the fire-place,
and  therefore does not reach  to  the  floor.   This is  frequently  the
cause of cold feet and much discomfort* We will make the opening
directly at the floor, (see Fig. 5, Lithograph plate,) and that forces all
the cold  air out,  warming and ventilating the whole room.   Here is
the whole problem solved in the most  beautiful and simple manner.
And you may exclaim,  as you see the simplicity and perfect working
of this, how came any one ever to think of anything else.
  Here, again, you see the value of that most excellent and valuable
       * Especially when the floor is cold—from a cold cellar underneath. 
Fig. 4.
 
 
             When Ventilation from Ceiling is Best.         43

of household arrangements, the open fire-place ; even without the
fire it serves a most important purpose.
  We  must not forget, however, that there are other circumstances
in which it will not do to depend on the fire-place alone for ventila-
tion.   Now, by leaving the fire-place  open, just  as  it is, and the
room full of warm air, we will simply change the condition of the
air supplied, and allow cold air to flow in at the bottom instead of
the top.   (See Fig. 6.)  There you see the fresh  cold  air simply
falls to the bottom and flows across the floor, without disturbing the
upper  part of the room at all.  It acts just the reverse of the hot
air let  in and taken out at the top of the room.
  Now it is very important for a clear understanding of this  sub-
ject that  we should  comprehend distinctly that  the foregoing ex-
periments refer only to cases where rooms are heated exclusively by
introducing currents of warmed air which has been heated outside
of the  room, but one-half of our rooms are not heated in this man-
ner ; they are warmed by heaters immediately in the room, such as
the common stove, the open fire, steam radiators, living beings, gas-
lights,  etc.  And then the conditions  are very different, requiring
an entirely different study and treatment.   The fresh air generally
comes  in  colder when thus warmed in the room, and consequently
falls to the floor and flows underneath the fouler and hotter air that
has been longer in the room.   We are also apt to be much deceived
by opening a window at the top, thinking the  warmed air will go
out there, or if cold air should come in it would be at the top of the
room and consequently do no  harm, whereas it not  unfrequently
falls like  a torrent directly  to  the  floor (Fig.  7), keeping the
feet cold while the  head is hot, and little children may suffer
much  with cold  in  this way while  the nurse's  head  or a ther-
mometer  hanging above the fire-place may  indicate a high tem-
perature.
   So you see we must first determine the relative temperature of
the air entering  the room, as  that, of  course, must be  considered
fresher than air that has been longer in the room;  if that is warmer
than the  air in the room, then there should be openings provided
for the escape of  the  fouler air from the bottom of the room.  If,
on the other hand, the air entering the room is colder than the air
longer in  the room, then there should  be an opening for the escape
of foul air from the top of the room (see Fig. 8).  All windows
should be made to lower from the top, as they are the great natural 
44       Circulation of Liquids of Different Densities.

ventilators, and are especially useful all  summer,  and always at
night the whole year.
  I have noticed another very interesting feature  in regard to the
circulation of liquids of different  densities; for  instance, suppose
we fill our little room half full with salt water, and  the remainder
with fresh water, we will  now apply a spirit lamp to the bottom of
the room (Fig. 9). As the salt water becomes heated it rises rapidly,
yet not to the top of the room, but only half-way, or to the top of the
denser liquid, and then  spreads across the room horizontally.  Thus
the salt water will keep up a rapid  circulation, and  may be  heated
almost to a boiling temperature underneath, and without heating or
disturbing the cold fresh  water above.  I have  tried  some  very
beautiful experiments of this kind with a number of liquids of dif-
ferent densities in the same vessel.   Gases of different densities are
probably influenced  in a similar manner by the application of heat.
And here we see the value of that beautiful law of  the diffusion of
gases, by  which each gas, no  matter what its density, is equally
diffused in all directions through  the  other gases,  independent of
temperature.*
  I desire to call your attention this evening to one other distinct
system of heating—I  mean  that  very  convenient,  economical,
cleanly, and  fashionable  system of heating by direct radiation
from  steam-pipes.
  As  steam  has become  such a common article in  all large build-
ings, both  for  power and as a convenient means  of  distributing
heat, most large buildings are thus  heated ; and as  a perfectly air-
tight building can be very  easily heated thus, and as most persons
are too ignorant or too careless to provide a separate and distinct
supply of fresh  air   simply  for   ventilation  alone, the  conse-
quence is, that this system, thus so  shamefully abused, is probably
drying up more talent and killing  more business men in our cities
than any other system in existence.   This applies especially to the
editorial rooms of nearly every one  of our leading newspapers and
publishing houses.   They  use  steam for  driving their  beautiful
printing presses, and the heating and ventilation, or rather the en-
tire want of  ventilation, in  their offices, would  indicate that  they
think that the same power which  drives their presses to  do the
printing  so nicely, is entirely sufficient to drive them to write the
* See second lecture, second course. 
Tiff.7.
 
 
            Want of Ventilation in Editorial Booms.       47

original articles for the printer, and that they have no more need of
fresh ai/r than their presses.
  You may think that I am certainly mistaken that so intelligent a
class of the community, who are building  such splendid fire-proof
buildings, such perfect palaces of iron and stone and marble, as our
newspaper establishments  are building in New York, Philadelphia,
and other large cities, would never make such a blunder as to omit
providing the most abundant supply of pure, fresh air to every em-
ploye in their establishments, and at all times, both in summer and
winter.
  Should there be any one present thus doubtful, I wish he would
undertake  to get  any one  of our enterprising  newspaper establish-
ments to publish in their paper an accurate intelligible account of
their system of ventilation, illustrating clearly the known quantity
of pure, fresh air delivered within using distance of each one of the
editors and employes.
  I think he would soon come to the same conclusion I have, that
the advice of the minister to his congregation  would be very appli-
cable to them—"Always do as I say, but never do as I doP 
LECTUKE III.
   In my first lecture, I endeavored to show how much we were suf.
fering from the effects of foul air, and the advantages to be gained by
supplying  ourselves all the time with pure  air.  Because we must
first feel that there is something  to be gained before we will  make
any great effort towards obtaining a given result.
  In my second lecture we considered the general principles governing
the circulation of air, the courses of its movements, the manner of the
action of heat upon different kinds of substances, which creates a con-
stant, ceaseless motion of  the  air, in all places, from the minutest
corked bottle to the vast currents that sweep over the face of the earth.
   Now, having learned the necessity for pure, fresh air, and  studied
the general laws governing its circulation, let us apply these  princi-
ples to every-day life.  To every-day  life ?  I should say e\erj-hour
life—nay, every moment of our lives;  for twenty times every minute
of our entire life, from the cradle to the  grave, do  we breathe what
ought to be pure air.  Is it always pure ?
   If we breathe one single breath, in  the entire day, of impure air,
it will weaken us, deduct from our capacity to attend to our daily
duties, or shorten our lives, in exact mathematical proportion to the
amount of  impurity in that one  single breath.   Now, we  breathe
twenty times every minute, twelve hundred times every hour, twenty-
eight  thousand times every day, and  nothing  but absolute and per-
fectly pure air answers the exact requirements of perfect  health.
   Well, you may ask, at  first thought, if fresh air is such a panacea
for all evils, and there is such  an  abundance of it  out of doors, why
not breathe it, and always enjoy perfect health ?
   Think one moment.  I eat my breakfast in the morning, generally
refreshed by a night of good sound sleep, (for I sleep with my windows
open.)   Immediately after breakfast, I enter the cars to come to the
city.  What a smell comes from the car as the door is opened! and
unless I wish to incur the displeasure, or provoke the indignation, of
almost every passenger, by opening a  window, I am obliged to sit in
that foul, offensive atmosphere, and breathe the poisonous exhalations
from my own lungs, and that from dozens of others, some of them,
it  may be,  badly diseased, (most persons' lungs  are diseased in this
country, from  breathing  foul air, and many  other diseases  besides
consumption are produced thereby.)
   Thus, in one half hour, I  have inhaled six  hundred  times  of this 
             Want of Ventilation in Occupied Rooms.         49

foul and poisonous air, and the blood has carried it to every portion
of my body, so that my entire system is  completely saturated, poi-
soned, yes, thoroughly poisoned by it, from the crown of  my head to
the soles of my feet.
  And thus is the day commenced.  Your blood is thoroughly poi-
soned before your breakfast is digested; for  your breakfast will  no
more digest without pure air than the  coal in  your stove will burn
without it.  You are subjected to  headache, dyspepsia, and a half
dozen other aches and pains, and are tired  out  long  before  night.
And thus you are killed long before you would die if  you breathed
pure air only.
   And  am I relieved from the difficulty when I arrive in the city?
   Start to-morrow morning at the Delaware  River, on  Arch or Wal-
nut Streets, or any other street, and go to the Schuylkill.  Inquire of
every individual,  in  office, store, dwelling or  factory, if he  knows
whether he had pure air to breathe all day,  or whether  he can tell
you, with any degree of accuracy, how pure  the air was in the room
he occupied for any hour of that day.
   I fully believe there is not one in ten—no, not one in a hundred—
of the  most intelligent men  in  that  entire  street, doctor, lawyer,
architect, or any other, that can give you an accurate  account of the
condition of the air breathed during any one  hour of the day.  That is
not all.   There is scarcely one in a hundred  that can satisfy you, by
an intelligent description,  of the means used for providing it:
   First—Assuming the air outside to  be pure, that there was a con-
stant, positive and sufficient supply of that outside air introduced.
   Secondly—That that pure air was not deteriorated by overheating,
or contaminated  by being mixed  with the  poisonous  gases  of  the
burning coal.
   Thirdly—That there was sufficient moisture added to it to com-
pensate for its increased capacity for moisture, due to  its expansion
by the  additional heat given to it, (which is  a very important thing.)
   Fourthly—That there was  any accurate, positive means provided
for insuring the fresh air to be brought within reach of the lungs
of those for whom it was intended.
   And, lastly—That there was a positive  means provided for  the
removal of all the poisoned air thrown from the lungs, so that none
could possibly be re-breathed.
   No;  you will  find them in  close,  unventilated offices, in close
factories, in almost air-tight  dwellings.   In  the large  stores they do
better. 
50         Want of Ventilation in Public Buildings.
   The  air is  very commonly overheated, it is often mixed with im-
 purities, and very seldom supplied with a proper amount of additional
 moisture.
   The air is often so  dry, that in a  few minutes' conversation the
 linings of the air-passages to your lungs become parched and husky,
 producing irritation  and a feverish condition of the system. And even
 in this room, to-night, do you see any opening at your feet, connected
 with a heated flue, for drawing the foul  air from the floor as fast as
 thrown from your lungs ?  I believe  there is not a square inch pro-
 vided for that purpose.
   Or,  do you see any escape immediately above  the  gas-lights, for
 carrying off the burned air while hot  enough to escape ?  Not one.
 There are two or  three  openings, I think, in the back  part of the
 room,  just  at the ceiling, but for  your breath to  get  there, it must
 rise and  pass by the  zone of respiration, and much of  it be  again
 re-breathed; and the products of combustion,  as we have seen, would
 cool sufficiently to fall  to the floor long before they reached that
 point.
   I take the liberty  of calling your attention  to this with more free-
 dom, because it does not indicate any special inattention  on the part
 of the Managers.   It  is not an exceptional case,  but it  is the rule.
 It is the popular opinion of the proper means of ventilation.
   Go with me, if you please, to that magnificent building, completed
 but a few years since,  at a cost of half a million of dollars, and given
 by its noble and generous founder to  the city of New York.   You
 will notice, inscribed above the entrance, cut in the solid stone, "To
 the Arts and Sciences."  Look in this reading-room—perhaps  the
 most useful  and most appreciated of any public reading-room in the
 United States.  See the large numbers of honest, industrious me-
 chanics, snatching an hour from their labors, to look over the current
 literature of the day.  Here, certainly, we shall find the most perfect
 arrangement for heating and ventilation that our knowledge of  the
 arts and sciences could suggest.  Let  us see  the  arrangements  for
bringing in the fresh air, for warming  it in cold weather, and for re-
moving the foul air.
  What!  no provision  for a  regular supply of fresh air ?  Not one
foot, not one inch—neither are there any regular flues for the removal
of the foul air.  And this most remarkable condition of things is but
repeated in the magnificent hotels, marble palaces used as offices, and
in many of  the new and splendid  colleges;  and, we  might almostj 
            Constant Care Needed to Provide Pure Air.       51

say, in all other buildings throughout the length and breadth of our
land.
   Thus you see how difficult it  is for one to mingle freely in the
society of his fellow-men, under existing circumstances, without being
subjected to being poisoned by foul air.  In going from here to my
home, to-night,  I shall have to ride in those cars, the air of which I
dread more than I ever dreaded  the small-pox  or cholera.   I have
been in hospitals where I have seen much of both.   They may slay
their thousands, but foul  air its tens of thousands.  And it is only
when I get to my room, where I shall  probably sleep to-night with
two windows well open, allowing the unobstructed breezes of half a
mile of open country to sweep through  my chamber, that I shall feel
entirely secure  from the contaminating  influences of foul  air, and
enjoy to its full extent  the  greatest of God's temporal blessings to
man—'pure air.
   I have no new patent idea to present to you, which shall secure to
you at all  times perfectly pure air, without any further trouble  on
your part.   There are no two constitutions precisely alike, any more
than there are  two human faces,  or two handwritings, and there are
no two hours in  our entire life in which  all the physical conditions of
our body are precisely the same.   It would be just as absurd, there-
fore, to go to a ventilating establishment, and tell  the proprietor to
ventilate your house or office, and pay the bill when it came in, and
content yourself by saying : " Well, I am glad this ventilating  busi-
ness  is done with.   I have got  my house ventilated, and the  bills
paid, and I am glad I am through with that vexatious business."   I
say this would be just as absurd as it would be, in case you had some
pain or ache, to go to your doctor and get some medicine, and therewith
content yourself, and say: "Well, I am glad this doctoring business
is over with; I have been  dreading it all my life.  I have been to the
doctor's at last,  have  been doctored, and  got my medicine and  paid
my bill, and so I am through with that  vexatious business."
  No—you must first feel that fresh air is worth taking some trouble
to obtain.   You must then make it a study  how to obtain it without
chilling or  overheating your body, in winter  and  in summer, at night
and in the  day time, when you are lying down and when you are sit-
ting up, before eating and after eating,  before exercising, while exer-
cising, and  after exercising—when you are well and when you are
sick, when  you are alone and when you  are in the crowded cars, or
in  a  crowded room, in wet weather and  in dry,  and for the  ever 
52        Jfotion—Agitation—the  groit Desideratum.

varying changes  of the external atmosphere—all these conditions
require separate and intelligent thought.
  In summer we depend almost exclusively on the natural movements
of the air.  To cause the air to move is then  the great matter.  We
must then remember that the great masses of air move horizontally,
not perpendicularly.   Of course, there are many little disturbing in-
fluences, but I mean the great mass of the air moves over the surface
of the earth in horizontal strata.  You can see this by the smoke of
the locomotive on the prairie, which can be seen sometimes for twenty
or thirty miles, stretching along just above the horizon.  All flues,
therefore,  are of little account in summer. We must depend on open
doors and  windows. Suppose you wish to ventilate your room in the
morning, the  air outside having become a little warmer  than the  air
inside,  and the upper parts of the window only lowered : the warmer
air would flow across the top of the room, leaving the air undisturbed
in the lower and colder part.  In this case, the window should be raised
from the bottom,  or a door opened  that would afford an escape  for
the air.
  But  again, suppose this same room to want ventilating in the even-
ing.   The  room has become warm through the day, and the outside
evening air is cooler than the room, and then,  if you raise the win-
dows from  the bottom only, the cooler air will flow across the bottom
of the room, leaving the upper part undisturbed and foul.
  No doubt you have all  noticed,  frequently, that in going into a
room in the evening, when your heads were above the window open-
ing, it  would be quite hot, but if you stooped down below the line of
the open window, it would be cool and pleasant. All windows should
be made to lower from the top, to meet this special case.  If you are
boarding,  or are so unfortunate as  to  be put  in a room where the
great blunder has been made of not having the windows  to lower, go
to the  nearest carpenter shop next morning,  before breakfast, and
get a  chisel,  and cut six  or eight  inches off  the little strip which
supports the sash, and, with a gimlet, bore  a  hole directly through
the sash, on both sides, and  with a nail you can keep the sash up in
its  place, when necessary.  I have had hundreds, yes, I suppose,
thousands, made  to lower this way  in the hospitals.
  Motion, motion is the great desideratum  in summer.  You have
all noticed, no doubt, how pleasant it is to go into a cool room, like a
parlor, that has been kept shut up  on a hot  summer's day; but in a
short time it begins to feel oppressive, and it is more comfortable to 
         The Effect of Different Temperatures on Flues.      53

have the windows open, and a circulation of air,  even if it should be
a little hotter than the stagnant cool air.
  Never sleep with closed windows  in summer.  It is in winter, how-
ever, that the greatest care is required in providing a constant supply
of pure air.  If  we would but accustom our minds  to comprehend,
readily and quickly, that cold air falls  and warm air rises, it would
assist us in our conclusions.  We all know that, of course, but we do
not practice applying it readily and quickly on all occasions.
  In summer, as I have said, the air moves horizontally, and  then
windows and doors  are the great means of ventilation;  but as cold
weather approaches, we must keep the windows shut, excepting when
in bed.  In winter, therefore, we must resort to flues for  the means
of creating a circulation, and for conveying the air from one part to
another.  A flue is simply a passage—a communication—for air of
different temperatures.  A flue  has no  power to create  a draught.
If the  air within is colder, it will have the power to fall;  if warmer,
it will be driven up.
  For illustrating this, I have here  some glass tubes about two  feet
long and two inches diameter.  This one (Fig. 8) has been lying on the
                                  table some time, and I suppose is
              Fi<r ft                             '         i i
                                  very nearly  the temperature of
                                  the air  in the  room.   I have here
                                  a little  tin box, which answers for
                                  a connecting tube, and over one of
                                  the  openings  I stand this tube,
                                  and by the smoke from this taper,
                                  first  held  at  the top, you see
                                  there is no current down the tube.
                                  And again, by holding the taper
                                  at the lower opening, you see there
                                  is no current passing up the flue.
But I will remove that, and place one (Fig. 9) over the same opening
that is warmer, and now you can see how jatrongly  the smoke is drawn
down through this lower opening, and see it flowing up this warm flue,
and out at the top.
  We will now substitute a cold flue (Fig. 10). This condenses the air,
and it  falls rapidly.  This action often occurs in the spring and early
part of summer, especially in the morning, as the external air becomes
heated, and the solid mason-work of the chimney remains cold, causing
a descending current,  which is often noticeable by the smell of soot
 
54                 Experiments with Flues.

in the room.  We will now add this tube, of the same temperature as
the room (Fig. 11), to see if the additional  height will not make an
ascending current.   But you see the smoke is still drawn down, the
Fig. 9.                            Fig. 10.
height of the  flue adds a little to its power, but the difference in its
temperature is the controlling force.
  We will now place another tube over the lower opening (Fig. 12).
Just see what  a wonderful effect that has !   Here is the air  rushing
Fig. 11.                               Fig. 12.
down this short flue and up the two cold ones.   We called those two
first pipes cold, but our  ideas of heat and cold  are simply compara-
tive; everything is warm, or has heat in it.   Perhaps some of us
think there is not much heat in the air when it comes whistling around
Dur ears 15° or 20° below zero;  but the cold rigid  chemist will still 
The Weight of the Atmosphere.             55
Fig. 13.
extract  many degrees  of heat from  that.   We must, therefore,
remember that absolute temperature has nothing  to  do with the air
passing up or down a flue—it is simply comparative temperature.
  Let me show you one more experiment.  Here are two tubes we
                               have had heated; as you  see,  the
                               smoke rushes up them rapidly.  But
                               now  we  will add  this  third one
                               (Fig. 13), which reverses the  cur-
                               rent at once.  The two first are hot,
                               taking the temperature of the room
                               as the standard, but the third one is
                               still hotter.
                                  The form of a flue  has but little
                               to do with the draught; the height
                               has a slight influence, but bear in
                               mind constantly that the great mov-
                               ing power in all flues is the variation
                               of temperature.
                                  Now, let us make a practical appli-
                               cation of this principle.
                                  Wait a moment:  just let  us lay
                               this one  aside, but not forget it, as
                               we shall want to  refer to it in a few
 moments, and try another experiment which has some  bearing upon
 the subject.
   I have here a tube just one foot square and two feet long, and one
 foot from the bottom there is what we will  suppose  to  be  an  air-
                       tight piston that  can be moved without fric-
                       tion.  Now, suppose  we heat that air 490°
                       (for the sake of easy remembering, say 500°);
                       this  would just double its volume—it would
                       then be two cubic feet in  size instead of one.
                          Now, suppose that, instead of  letting this
                       air expand, we should put a weight on it, so
                       as to keep it  in its place, how much do you
                       think we  should  have  to place  on?   Two
                       thousand  one  hundred and sixty pounds, or
    /    X  ~\    about one ton-  Now'whafc do we find these
 ^ -   TT 'S-Jb   2160 pounds to represent? It is the weight of
 a column of  atmosphere with a base  of one foot square, or fifteen
             ■4
Fig. 14.
 
•r>o"                   Ventilating a  Church.
 pounds multiplied by 144 square inches—it is the weight that would
 rest upon the piston if all the  air was taken out from under  it.
 Therefore, if  you add about 500° of heat to a cubic  foot of air, it
 makes it two cubic feet of air;  or, if you attempt to keep  it from
 expanding, you must put a ton weight upon it.
   Mark one thing, however, if it takes ten ounces of coal to heat that
 air to 490°, which we do by piling our ton weight  upon it, it will
 take fourteen  ounces of coal if we  allow it to expand to two feet.
   In  the former case, where the air remains  stationary, it had done
 no work.   It was ready to go to work, but  it  had not commenced.
 But in  the case of its expansion, it had done  a great work.   What
 was it?  Why it  had lifted that ton of atmospheric air one  foot in
 height,  and that work was what used up the difference between ten
 parts and fourteen parts of coal (I don't trouble you with fractions).
   You see, therefore, to make the air quit the earth and  ascend into
 the upper regions, requires a positive power, the  same as it  does to
 drive some poor simple people away from the fire on a  cold day.
   We often say that, by heating  air, we give  it power  to ascend;
 instead of which heating it destroys its power to maintain its position.
 It weakens—enervates it—so that its  neighbors easily  drive it out
 and take its place.
   One cubic foot  of air, diluted  to two feet, would be driven about
 two miles and a half high before it found any body as weak as itself,
 for every  350  feet in height, in round  numbers, the pressure dimin-
 ishes  by an amount  equal  to  one degree,  or forced under  water
 thirty-four feet reduces it to one-half its bulk.
   Now, let us  go  back and finish our syphon, or flue experiment.
   Here we have our little glass house again*  We will take the roof
 off and put a pretty large family in it—I  mean large in numbers, if
 not in size.  You may call it a school, or public meeting, or church,
 or whatever you  please.   Suppose, for  illustration,  we call it  a
 church,  and we will call this larger light in this end the minister
 speaking to the congregation.   You see,  the lights are a good deal
agitated, and flare around a good deal.
   There is a rush of air down at this end,  and, as it becomes heated,
it rises at the other.   Let us cover about one-half  of this  up.   Now
see what a rush of air there  is down these flues, instead of up them,
as there ought to  be.  Here, you see, the main body of the building
though  much  shorter than  the  flues, forms  the heated leg of the
 syphon;  and you  may thus  recognize why many of the  ventilating
                        * Fig. 5, page 25. 
             Bad Ventilation in Philadelphia Church.         57

flues, put in the cold outside walls of many of our large builaings,
persist in working the wrong way, and  cold  air blows  down there,
instead of the foul air going up.
  But there seems to be too much draught.   Let us put the roof on.
Ah,  that is better;  but,  then, what a draught there is down this
chimney-flue.  Call the sexton,  and have that stopped up quickly, or
those sitting near the:re will soon catch their death of cold, and will
never come here again.
  You see, however, they shine  very brightly, notwithstanding  all
the draught,  but there, now, it is all closed up as snugly as the most
fashionable church in town. See how quiet and peacefully they burn
now.
  Ah, there is one just  gone to sleep.   You must  excuse him, he
probably was up most of the  night with a  sick child.  And there
goes another.   I think he must have been  very  busy for the last
week settling up his last  year's accounts.  Just see,  they are going
to sleep so fast, I don't  think we can  pretend  to  give excuses for
them all.
  And, now, is not that a brilliant congregation to be preaching to?
Every one dead asleep excepting the preacher himself, and I suspect
he feels stupid  enough to go  to sleep, but it would  not look  well;
and he has to tax his energies so severely he will hardly get over it,
so as to be good for  anything for the balance of the week.
  You may  think this an  exaggerated representation of  the real
facts.   Do not deceive  yourselves.   A  few months since I was
requested by one of the congregation to visit a building within a few
minutes' walk of this place, and  see if there was not  some defect in
the ventilation.  The gentleman stated  to  me that he sometimes
attended the class-meeting, and would  be glad to  go  oftener, but it
was held in the  basement story,  and it was quite impossible for him
to keep awake,  as he  had to get up and go out two or three  times
during the evening, to get  a little fresh air, or he could not keep awake.
  I examined it.  The ceilings were low—only nine  or ten feet;—
then there were two  old leaky portable furnaces, which were used as
occasion required for heating the large room  above, or the  basement
room when the class-meeting was held.
  The only ventilation they had was to let off the surplus heat (if
they had any, which was seldom) into the  room above.
  Now for fresh air.  By a very careful and minute  examination, I
discovered a  little pipe (I think it was  about six inches in  diameter) 
58   Frescoed Ventilator on Ceiling of Washington  Church.

to each stove (both of which would not be over half as large as what I
have to supply my own bedroom), for the supply of  the fresh air for
that whole congregation.  Fresh air, did I say ? Well, let us see where
this fresh  air comes from.  The janitor,  after taking us down and
showing where he kept the ashes, wood, old benches, and ali sorts of
rubbish, was about  going up, but  said I,  "Where is the part where
you get the fresh air to the furnaces?"  " Oh,"  he said,  " he could
not get  to that, it was such a rough  place, and there was a sewer or
gutter (from the adjoining graveyard I suppose) running right across
it."   And from that place, too rough to be got at, with an open sewer
running through, and  too  foul to go into, was  where they got the
fresh air (!) from for the whole of that congregation to breathe.
   And do you suppose this is an exception  ?  Let me tell you.  During
the  first year of the late war I was  called upon  by the Sanitary
Commission to examine the hospitals in Washington City with refer-
ence to their ventilation.   A large number of the  churches  in that
city were used for hospital purposes, and  many  of them  were heated
by hot-air furnaces, and in not one single  instance had they fresh air
boxes to them, neither had they any means for carrying off the foul
air.  The furnaces  were  generally placed in  a hole excavated under
the main  part of the building, and all the ground around them left
exposed, and the air was  sucked in from the fermenting, decaying
vegetable  mould under  the  building.  And this place around the
furnace was the place where all the filth and old rubbish was thrown
to  get it out of the  way, and it was thoroughly out of the way too, for
the surgeon in charge or any inspector never got there to see it.  In
some cases I found this space  around the furnace  used as the dead
 house!
   Did  I say there was no attempt in any of those buildings for syste-
 matic ventilation ?   I ought to have made one exception.
   I called  one  morning  about ten o'clock  at one of the finest new
 churches, which was then being occupied* as a  hospital, and asked
 for the surgeon in charge.  He had not arrived.   (They did not often
 venture in before eleven o'clock, the wards became so foul during the
 night it took till that time, with the windows up, to get them fit for
 the surgeon in charge to venture  in.)   I  inquired of the wardmaster
 how the building was ventilated.  " Oh, very well—very well, indeed
 —they .had good ventilation," pointing up to a  large, spleudid venti-
 lator in  the ceiling.  "Do you keep that always open?"  I asked.
 " Oh,  certainly," he  replied.   But I always have a great suspicion 
Ventilation of School Houses.
59
of those ceiling ventilators, as they are generally shut.   So I walked
around the ward, and when under it asked him again if he thought
that was open.   A smile came over his face as he discovered, for the
first time, it was a handsome fresco  painting on the solid wall.  And
this was the  only practical  systematic attempt at any ventilation in
any of the church buildings used as hospitals in all Washington.
   I have  not been in any of the public schools in this city for many
years, but a gentleman told me the other day that he called at one of
the  fashionable schools  up  town to get his son and  take  him home
under his umbrella, as it had commenced raining since morning, and
as he opened the school  room door he was perfectly shocked, as he
staggered back from the gust of  horrible foul air that came rushing
out of that room.
   I have  examined most of  the public schools in New York since I
have those of Philadelphia.
   They have a way of their own of doing public business over there.
There has been a good deal said about ventilating public schools of
late years, and as it was such a scientific  and fashionable matter they
must have their schools ventilated of course.
   I was very unfortunate  in  my intercourse with the Directors of
the Public Schools.   I did not  happen to meet with many of those
high toned, liberal,  scientific gentlemen that are on  many of the
committees, of course.
   Those  beautiful and ornamental gratings called  registers are
accepted as the external proof of good ventilation, suggesting as they
do the flow of an abundance of  pure  fresh air.   So registers  were
bought freely and put in all the rooms, top and bottom, with splendid
red and green and blue tassels, altogether making a  handsome  show
and doing the very able  and scientific gentlemen  on the School
Boards great credit for their enterprise and great care for the welfare
and interest of the pupils under  their charge.
  Now, let us examine the  operation of  these registers.   Holding a
handkerchief in front of them, there it remained perfectly motionless.
It neither blew hot nor cold—it was perfectly lukewarm, motionless.
Go to another—the same.   And  to another—the same.  Well that is
singular.  Let  us go on the roof and see what can  be the matter.
A careful  search fails to discover any flues at all, but a mechanical
examination  shows that the coping-stone  has been put  on them,
making all the flues  as thoroughly air-tight as the solid wall—more
perfectly capped  than  that  chimney.   There had been no attention 
60            Want of Moisture in School Houses.
 paid to having the holes  for  the ventilating  flues cut through  the
 coping-stone.
   Yes, I believe that to-day a large proportion of all those flues with
 the  elegant ventilating registers at the top and bottom of the room,
 are  capped and made as thoroughly air-tight as  the solid wall, and
 are  as perfect shams and as useless as the elegant frescoed ventilator
 on the solid wall of the church hospital in Washington.
   I do not believe that  Philadelphians  have gone  quite thus far in
 satisfying  the public demand for ventilatipn in the public schools.
 They  may  not  have done any more, but I believe they have not
 pretended to do quite as  much.
   Excuse me a few minutes; I must illustrate  another  very great
 deficiency.  The simple illustration I will give you represents almost
 the universal condition of our  hot-air furnaces.
   Much complaint was made of the uncomfortable feeling in one of
 the large public schools, where they had some 1200 or 1500 scholars.
 I was  called to examine  it.   I asked, as is my usual  habit, if they
 evaporated plenty of water.  "Oh, yes; they had given the janitor
 full  directions about keeping the evaporating pans always full."   I
 found  the evaporating pans full, sure enough, rather to my surprise,
 but what do you think they were filled with?  Several old brooms,
 half charred, and  some  old water  buckets all  fallen  to pieces, and
 other rubbish thrown in there  out of the way.
   And now those of you who have been  trusting to your servants  to
 keep water in  your furnaces, if  you will take a candle when you  go
 home  and go  down and examine  your own furnaces, you will  most
 likely find them dry, and if you go to the public schools in the morning
 you will see that they too are not an exception.
  I wish I had time  to explain the  dreadful effect of this want  of
 moisture in  all our artificially heated rooms.   The air in winter is
 very dry, the moisture is squeezed  out as the water  is squeezed out
 of this sponge.  But as  you heat it you enlarge its volume again,
 and it  sucks up the moisture just as this sponge  does, and if you do
 not  supply  this moisture in other  ways  it  will  suck the natural
moisture from  your skin and your lungs,  creating that dry, parched,
feverish condition so noticeable in our furnace and other stove-heated
rooms.  Few persons realize the great amount of water necessary  to
be evaporated  to produce  the natural condition of moisture  corres-
 ponding with the increased temperature given the air in many of our
rooms  in winter. 
Exercise gives Bright  Cheeks and Sound Sleep.      61
  I have  copied a table  expressing in grains  troy the moisture con-
tained in one cubic foot of air when saturated:
         Degrees                                  Grains of vapor
        Fahrenheit.                                  iu cubic foot.
           10............................,....................................  -8
           20................................................................  1.8
           30..................................................................  2-
           40.................................................................  2 9
           50..................................................................  4-
           60..................................................................  6-
           70..................................................................  8-
           80.................................................................10-
           90.................................................................15-
           100..................................................................19.
  Thus you see, taking  the air  at 10°  and heating  up  to 70°, the
ordinary  temperature  of our  rooms,  requires about nine times the
moistue contained in the original external atmosphere,  and if heated
to 100°, as most^of our hot-air furnaces heat the air, it would require
about twenty-three times the amount in the external atmosphere.
  This is a very interesting and important subject, but I am sorry I
have  not  time for further explanation.
   I see some kind friend has been around and opened the doors of
our meeting-house and awakened the sleepers.   And now you see the
lights  shine, and the cheeks glow as brightly as would those of our
young ladies could they be persuaded  to  go  skating,  or take a five
mile walk every day, rain or shine, and sleep with the windows open,
and never ride in any of our cars, or go to parties or any other public
gatherings unless  the buildings  where they are held are well  venti-
lated.
  But those  dreadful  drafts !   People  will not bear them.  Let  us
see if we  can accommodate them.  Put on the roof, and here comes
this dreadful current again down the ventilating  flue.   Well,  venti-
lating flues have the  name of being  great humbugs.   Let us shut-
them  up.  There are your poor consumptive patients—there they go,
you see.   One-half dead already, and the rest will soon follow if we
cannot rescue  them.   Let us open the flue again.   See how they
brighten up as the fresh  air comes in.   There is no use of disputing
about it, you must  have a current of fresh air coming into the house
or you will surely  die.
  Now let us change  the programme.  Let  us  build a fire in this
fire-place in the lower story—that burns up brightly.   Where doe's it
get fresh air from now ?  There can be no current down the chimney. 
02         A strong Fire draws the Air from Sewers.

Let us search it out with this smoking taper.   Ah, here it is coming
down through the ventilator from the very top of the house.  We will
soon stop that by this cap.   But  see, it still  burns as brightly as
ever.   Let us try again.   Ah, do you see the  smoke  rushing down
the second story chimney and across to the stairway, and down the
stairs, and across the room again to this fire ?
   There is a valuable hint.  Have  you not noticed frequently gas in
the room from the fire-place  or stove, and especially at night ? And
do you see how easily it would be  to account for it if the house were
shut up tight at night, with a large fire in the  kitchen or furnace in
the cellar, and but a small fire in the second story?   Don't you see
how the whole  products of combustion, all the poisonous gases, may
be drawn out into the room  ?  You often notice accounts of whole
families  being smothered to death in one  night, but many seem to
think if they are not smothered to  death the first night, that it is not
so very dangerous after all, and not knowing how to remedy it easily
go on from day to day and sometimes escape the whole winter with a
little of their lives left.
  Now, let us put out  the fire in the first story and make one in the
second.
  You must remember  that this is not a fashionable double ceiled
and plastered air-tight house.  It is much more  open, in proportion
to its size, than any ordinary house. And now, as this lower flue has
been so  highly heated,  it may take some  time  for  the  fire  in the
second story fire-place to become heated  sufficiently in excess to
cause the air to  draw down  the longest flue  to  the  bottom  of the
house and up the stairs to the second story fire-place, but  it will soon
do it.
  I wish you  to notice one  thing here particularly,  and each one
apply it to your own particular case.  You know the lower part of
the house is closed up  tight to keep out the robbers, and if great care
is not taken to give an abundant supply of fresh air to your chambers
otherwise, it will be drawn up through  the  hall out of your kitchen
and cellar, and as the cook  has left the range lid off and  shut the
dampers, you will have a suffocating smell of gas all over the  house.
But the worst danger of all is the air that may be drawn in from an
untrapped  sewer  or cesspool.  This is a very  common but  great
source of ill-health.
  Sanitarians have  given much attention to this subject  lately, and
have been astonished at the magnitude of the evil.  I have long main- 
Epidemic at Maplewood Institute.             63
tained that a family might go to the highest and most healthy location
in the world, and by a little carelessness might accumulate sufficient
filth around them, and by closing up the house at night and allowing
the foul gases from untrapped sewers and cesspools to enter through
the halls  to their sleeping rooms,  to thus make what would other-
wise be a healthy place a very unhealthy one.
   As a case in point, I would refer  to a very interesting report of
Doctors Palmer, Ford, and Earle, giving an account of their investiga-
tions of the causes of a severe epidemic that occurred in  the summer
of  1864 in a young  ladies'  seminary in Massachusetts.    " The
Maplewood Institute" is situated in Pittsfield, one of the most beau-
tiful of those charming New England villages,  which,  to external
appearances, are the very emblem  of all  that  is pure and healthy.
Yet even  in this  lovely place, from an ignorant or  careless arrange-
ment of the drains and cess-pools, much of the foul  gas generated
there found its way into the building,* making sixty-six out of seventy-
four young ladies  sick, fifty-seven of whom had the  typhoid fever and
thirteen died.   Many similar  cases  are frequently occurring, some
few of which, like  this,  are  carefully investigated,  and the causes
removed.   Many  more, however, go unnoticed, and are  accepted as
special dispensations of Providence, when it  is all due  to our own
negligence.
   I want to show you an arrangement  that ought  to  be in  every
house.  We have seen the power  of a fire to create a  draft, and if
you will think a little you will notice that the kitchen fire is the most
considerable and most permanent  power in ordinary  dwellings, and
this ought to be  made  use of to ventilate the kitchen, water-closet
and bath-room in every house.   But you must not make an  opening
directly into the  kitchen flue; if you do  you will interfere with the
draft of the kitchen fire, and if you interfere with the kitchen fire
you will soon wish yourself at anything but keeping house.
   But we can easily get  over that  trouble.  We' will use this square
glass box again to represent a flue.   I don't mean this to represent the
size—it ought to be  twice that size.   In the centre we will put a cold
pipe, to show you that a pipe without any heat in it would only cause
the foul air to tumble down into the room.  Thus you see the smoke
descending.  We will substitute a  pipe  with a  gas  light to heat it.
  * In addition to which there appeared to be a deficiency in the arrangements for
ventilation. 
64 A Ventilating Arrangement that should be in Every House.

Now you see what a rapid current there is out of this large flue. See
what a  splendid arrangement this is for ventilating, and it may be
extended so as to ventilate the whole  house.  It is not necessary that
the room to be ventilated should                -p-  15<
be adjoining, but a pipe can be
carried between the floors 50 or
100 feet.
  I had  an opportunity, during
the late war, of thoroughly test-
ing this system of  ventilation in
the government hospitals.
  Let me  say here that a very
common mistake in making ven-
tilating flues is, that they are en-
tirely too small to be of any value.
One  of these little Philadelphia
flues, four  by nine inches, made
with rough bricks,  and nearly or
entirely choked  up with mortar,
as many of them are  frequently
found,  is of no account.  They
are simply  a deception, and a perfect provocation to a sensible man.
  I commenced by making some  in  Washington, for single  wards,
thirty inches square, but in St.  Louis, and Louisville, and Nashville,
where buildings four or five stories high were used for hospitals, I
made them much larger, some three feet square and some four feet
by six feet.  Some buildings, where  the ventilation was so bad and
the water-closets were so offensive that the government had to abandon
them, I  had ventilated by  these immense shafts, heated by  the
kitchen and laundry  fires, which proved  thoroughly efficient and
entirely satisfactory.
  I had hoped  to have time to  discuss the  subject  of heating more
fully in connection  with ventilation, but cannot; but I will state, in the
simplest manner, a few of the leading points first.
   You must have fresh  air all  the time.  In summer you  can get it
by opening the  doors and windows.   In winter it  must be warmed
before entering the room.  It must not enter the room cold and flow
across the floor to the other side before it reaches the heating appara-
tus.   You  can  bear a large amount of fresh air if it strikes you in
the face and evenly over the whole body, but never let a jet of cold
air blow upon any small portion of your body.
 
Different Methods of Heating.
65
  To avoid these local currents sucking in at cracks, you must make
provision for the introduction of an  amount of air larger than the
sum of all these cracks, and your exhaust flue besides.  This air must
be partially warmed before  entering.   If this is  done by a hot-air
furnace, it must have  a large fresh air box, which  should  be  from
eighteen inches to two feet for a large house.  It should have a large
evaporating vessel,  with  a ball-cock to supply it.   You cannot get
the servants to attend  to it, and you must never allow the air  from
your cellar to  enter your furnace to be driven up stairs.  Never
allow the furnace to get red-hot.
  A hot water  furnace disturbs the natural conditions of the air the
least, and,  on that account, is a  very healthy means of artificially
heating air.  But they are necessarily expensive, and so few persons
really  appreciate the value of pure air, that but few will go to the
expense of introducing them.  It is a mistake to suppose  that they
do not dry the air, so to speak.   You cannot elevate the temperature
without increasing the capacity for moisture.   A hot water furnace,
therefore,  requires  the  artificial  evaporation of water  to  give the
warmed air its true hygrometric condition.
   Heating the air by  steam is the next most healthy means; as the
surfaces used are heated a little hotter, less of it answers the same
purpose.   The first cost is therefore  less.   It is the most rapid and
convenient means of conveying heat to any distant  point of anything
now in use.  Under the pressure of an ordinary boiler it will travel
seven  miles in  one minute.   The time I hope is not far distant when
the  subject of heating  and ventilation will receive an amount  of
attention due to its importance.  I believe then we shall have steam
pipes  laid  through  our streets, the same as gas and water now are.
The present  system of each man keeping up separate fires all over
his house is as crude,  and extravagant, and unnecessary as it would
be  for every man  to  make his own gas or have  his own well  for
water.
   Where a steam furnace is used, two-thirds of the heating surface
should be put below the floor and fresh air brought into it, and from
there conducted to the rooms through large pipes.   This warmed air
should be  let into the room at  the  floor,  and  an opening  into  an
exhaust flue, two-thirds the size of the inlet, should be provided  at
the floor for the escape of the foul air.   The remaining  one-third of
the heating surface should be exposed in the halls and  some in the
other  parts of the house, to heat by direct radiation, but under  no 
66      Dampers in Cold Air Boxes  Generally  Closed.

circumstances  should a room or office be occupied heated exclusively
by direct radiation from exposed steam pipes.   It is one of the worst,
most unhealthy, killing systems in existence.*
  Steam furnaces require the evaporation of  an additional amount
of moisture as well as  any other system of heating.  According to
Dr. Wetheral's investigation,  it would  require  the  evaporation on
some days of nearly forty pounds of water every minute in the Senate
Chamber to maintain the  proper hygrometric  condition.  Probably
one of the very best arrangements is to  have a good  steam furnace,
with a large fresh air box letting in an abundance  of air moderately
warmed, and overflowing the house with this, and some direct radia-
tion in the  halls, and a good, bright, cheerful open fire in the family
sitting-room.
  But if you  cannot  have a steam  or  hot water  furnace, you  can
make a room very comfortable indeed with  a  stove, if you will  but
introduce all the fresh air required for the room directly against or
on top of the stove.  No stove  ought to be put up without having a
supply of fresh air from the outside, and a large evaporating vessel,
kept constantly filled with water, with an opening  in the heated  flue
near the floor for the escape of the foul  air.
  In conclusion, allow me to urge upon you to  examine your furnace
this evening or to-morrow morning, and  if there is no fresh air  box
communicating with the external atmosphere, go to the  nearest car-
penter's shop before going to your business, and get him to come at
the earliest possible moment and put in a good large one, and if he
asks you where you want  the  damper in the cold  air box, tell him
you don't want any.
  Dampers in  cold air boxes are handy  things to have in the house,
when used properly, but, like fire-arms, are very dangerous if you do
not understand them.   Yes, dampers in cold air boxes and  other
contrivances for keeping the fresh air out of houses, have killed more
persons than all the fire-arms ever made  in this country or any other.
  If you have no evaporating vessel in the  furnace, stop at your
furnace man's, and tell him to put in two good large  evaporating
vessels  in  such  a position that they will evaporate two or  three
buckets of water a day in cold weather.
  And if you have a stove at your office, stop on your way down and
buy a good large earthen pan  to  set on  the  top  of  the  stove,  and
keep it  always full of water.   Make  a pipe for the inlet of fresh air
to every stove over which you have  any control, and never remain
  * 3Iy views have somewhat changed with regard to heating by direct radiation.
See last lecture. 
Escapes for Foul Air at the Floor.
67
in a room one day without a good opening at the floor for the escap3
of foul air.
  And from my own experience, and that of  many others whom 1
know to have given much attention  to this subject, I can assure you,
with the  fullest confidence, that you will be  most amply rewarded for
your care in this respect by increased health, strength and happiness.
and by the reasonable prospect of a long life. 
\ 
          SECOND    COURSE,


DELIVERED   BEFORE THE  FRANKLIN  INSTITUTE,

                  DURING THE WINTER OF 1867-68.
                          LECTURE I.
   Perhaps no subject relating to  the health of the human system
 ever gained favor more rapidly, (without advertising,) than has the
 subject of ventilation within the last year or two, and  I think we
 may refer to the report of the Board of Health, for the year 1867,
 as a substantial and most gratifying proof of this assertion.
   In the year 1865, there were 17,169 deaths in this city; in 1866,
 chere were 16,803, and  in the year  1867, there were only 13,903,
 or a saving of 2,870 lives in the last year, and 3,237 in the two years,
 and this,  too, notwithstanding an increase of  population probably
 equal to 20,000 per annum.
   The  saving to the  citizens of Philadelphia by this  diminished
 mortality, and the sickness represented  thereby,  could  be scarcely
 less than three-quarters of a million a year; or sufficient to pay the
 entire expense of our excellent system of public schools.
   Could this decrease in the rate of mortality be continued we would
 soon be a very healthy  people; perhaps this is almost too much to
 hope for.   I do  believe, however, that this rate of decrease  in the
 mortality may be continued through the year 1868, and with a cash
 outlay,  if judiciously expended, no greater than will be returned  to
 us penny for penny and dollar for dollar within  twelve months
 thereafter.
  No healthy condition of the human frame can be maintained
 without we breathe pure air, and although there has been a wonder-
 ful improvement in this respect within  the last few years, yet we
 still do not breathe pure air one-half our time.
  Our arrangements for the artificial ventilation of our houses in
 winter and at night, are still exceedingly imperfect.
  The great majority of our citizens scarcely realize the true value
of pure air, or  hardly know how  to obtain it economically at all
times.   We need more public education on this subject.
  There has long dwelt in the minds of many persons a kind of 
70        Public Apathy in Regard to Ventilation.
 vague idea that ventilation was a good thing in its way ; but with
 nine-tenths of the whole people, the chief concern has been to obstruct
 all circulation of air, to stop all draughts, and thus  practically to
 prevent any ventilation, especially in winter.
   In the good old  days of open wood fires, when, as in our child-
 hood, the real chimney-corner was the family sitting-room, so to
 speak, or at least, for the children, then, with all the listing of doors,
 caulking of windows,  and filling up  of key-holes, there was certain
 to be  still an abundance of  fresh air, that would force its way into
 the room in spite of all efforts to keep it out.  But with the intro-
 duction of anthracite coal and air-tight stoves, and still worse, steam
 pipes, placed in the room for heating by direct radiation, the stop-
 ping of all draughts that were before so annoying, became a matter
 of easy accomplishment.
   The results  thereof have been perfectly frightful,  persons have
 thus unconsciously been smothered to death by the thousands and
 tens of thousands.
   It seemed almost impossible to arouse the public from the quiet,
 satisfied' stupor that followed their  great victory  over their  old
 enemy—the whistling winter wind.  Those  that have not  gone to
 their long homes during  this dark winter-night  of stupor and
 ignorance, may well rub their eyes in astonishment, as they awake
 to a   consciousness of the dangers they  have so  marvelously
 escaped.
   The poor man, too, as well as the rich, should feel that he has no
 truer or  more valuable friend on earth than fresh air.  His food,
 though coarse and simple, will digest more fully and  quickly with
 an abundance of pure  air.   His head is clearer, his chest expands
 and his muscles grow  stronger, as his heart grows  lighter, and he
 goes cheerily on day after day with his  laborious toil, returning at
 night to  his home  and fireside, surrounded by his wife and little
 ones, a happy man, made so by the  consciousness of having been
 able to do and having done a good day's work.  He enjoys a night
of sound sleep, when sleeping with open  windows, and wakes  re-
freshed in the morning, ready again to commence the toils of another
day.
  The Doctor's explanation of the physiological effect of breathing
air, whether pure or impure, is very interesting.
   We  cannot, of course, expect to go into a regular medical or physi-
ological lecture at this  time,  but we must just examine some of the 
The Action of the Lungs.
71
main points so as to get a general idea of the effect produced by air
of different qualities, and if possible, to form  some conception of
the manner of its action. I have here a little arrangement by which
I wish to represent the action of the lungs.*  It is simply a glass bell
jar with a piece of rubber stretched over the bottom,
which is intended to represent the human diaphragm.     Fig.16-
From the  mouth of the figure-head  there is a small
tube extending  downwards,  and this represents the
wind-pipe, at the end of this is another  piece of rub-
ber,  which we will suppose  to represent the lungs.
Now, as I draw down the diaphragm, the space in the
jar  is enlarged, and a partial vacuum is created, and
the air  rushes down  the wind-pipe to  fill the space.
It is prevented, however, from getting  directly into the body by
the lungs, which being elastic, or rather all folded up in innumerable
little folds,  expands and contracts with great ease.  The  power,
therefore, does  not lie in the lungs so much  as in the diaphragm
and ribs, the air is forced out and in the lungs, similar to the manner
in which it is forced out and in a pair of bellows.
  The lungs are composed of an immense number of air-passages,
with innumerable branches, we might say, perhaps, like the branches
of an apple tree, and at  the extreme ends of these branches are air-
cells instead of  apples.   The number of these little cells  is esti-
mated by  some to amount to six hundred millions.
  The aggregate surface of all these air cells is variously stated by
different physiologists from 600 to 1500 square feet.  So, if this room
was 30 a 40 feet, the surface  of the lungs of a single person would,
if spread out, be sufficient to  carpet the whole  room.
  These air-cells are perfectly surrounded by a complete net work
of minute blood vessels, through which flows the dark, impure
blood that has just returned from the most extreme points of the
body, bringing with it,  dead, diseased,  old, worn  out  particles of
the body,  and the carbonic acid, or what we might call the ashes
resulting from the combustion of the oxygen, which is constantly
required to keep up the heat  of the body.
  Now,  it is when this impure blood on  one side meets the pure air
on the other, that the most  wonderful change takes place.
  This membrane of these  air-cells of the lungs is so exceedingly
                 * Griscom's " use and abuse of air."
             5
 
 72   Different Effects of Pure and Impure Air on the Lungs.

 delicate, that there is a chemical transformation or exchange takes
 place at once.
  The  carbonic acid, and other impurities from the  blood, pass
 through this fine membrane of the lungs, and are absorbed by the
 air, while the oxygen of the newly breathed air passes through the
 lungs into the blood, which is thus changed from  a dark color
 to a bright, light colored red, and oxygen  is thus carried to the
 hundreds of little capillaries in the most remote parts of the body
 to the skin and to the bones, to the brain and to the stomach, and
 there burned to  keep up the heat  of the system, and to cook the
 food we have eaten, (if the Doctors will allow me to express in that
 homely manner, the beautiful and very elaborate process in which
 the fresh air we breathe acts in digesting and utilizing our food.)
  But  suppose, instead  of the air  thus introduced  into the lungs
 being pure, it is impure, or already loaded or charged with carbonic
 acid by previous breathing, then it cannot take up the impurities of
 the blood, and instead of its being changed by the  absorption of
 oxygen to  a beautiful bright red, it  remains of a dark, dull color,
 consequently these impurities have to be carried  back to all parts
 of the system, instead of the much needed oxygen; disarrangement
 of the whole system soon follows to a greater or less extent, accord-
 ing to the proportion of the impurities in that air.
  The little air-cells of the lungs also become choked  up with this
 refuse material, which causes what is familiarly called consumption.
 You all know  if you allow the ashes to accumulate  so as to fill
 the  entire space underneath  the grate, that the grate will soon be
burned  out.   In a manner very similar to this will that exquisitely
thin, delicate membrane of your lungs be destroyed, if you neglect
to breathe sufficient pure air to carry away all the ashes from the
immense numbers of fires constantly burning in your body.
  The frequency of these interchanges between the air and the blood,
the  very large aggregate amount of each that daily passes  through
the  lungs, ought to impress us with the great importance of a careful
attention to maintaining the best conditions for perfect health.
  But, in too many cases, our estimate of the value of things is
based upon  the  dollars and cents it costs us, and as no patented
 monopoly has ever been able to control the supply of pure air, so  as to
 dole it out to us by the dollar and cent's worth; and though it is kept
 constantly poured around and over our houses in the most lavish 
Amount of Air breathed Daily.
73
10
15
20
 i BBBBBEBBBBBBBBBBBBBB
 2 ■■■!■■■■■■■■■■■■■■!■■
  B IBBBBBBI !■■■■■■■■■■■
 4
 6
 6
 7
  ■■I!"Ii!Si ■■■■■■■■■ui
 9
10
n n~
 profusion, yet we have in many cases treated this wonderful bounty
 of the Creator with shameful neglect.
   I have prepared a diagram by which I hope to impress upon your
 minds the amount of air breathed by each individual in twenty-four
 hours.   It is  18 X 20 feet, and intended to represent one foot thick;
 this gives 360 cubic feet of air, or  125 times the whole bulk of a
 man.  The space included within the outline 10, ab 18, Fig. 17,re-
 presents the proportion of oxygen in the air breathed, the  whole of
 the air breathed being indicated by the entire figure.
   This, of  course, is given merely  as  an average.   The amount
 breathed varies very greatly from many causes;'—some persons may
 breathe at times nearly double
 this amount, and at others not                Flg"   *
 half so  much.   The average
 number of respirations is  es-
 timated at about 20 per min-
 ute, and  the  amount  inhaled
 at each respiration is about 20
 cubic inches.
   We do not completely fill
 and empty the lungs at each
 breath, on  the  contrary, the
 lungs contain  150 to 200 cubic
 inches of air, so that about
 one-eighth  only of the con-
 tents of the lungs is changed at each breath.  I believe Physicians
 have scarcely  determined  positively how this air remaining in the
 lungs is quickly and constantly purified.
   The diffusion of gases, which I hope to explain in our next
 lecture, has  much influence, no doubt, in removing the excess of
 carbonic acid  from the remaining air, and saturating  the freshly^
 entering air before it is  inhaled.
   Some  physiologists  explain,  that  the carbonic acid and  other
 impurities, are expelled from the minute  cells by the muscular
 contraction of  the circular organic fibres, and are thus delivered
 into the larger branches in which diffusion at once takes place with
 the air just introduced.
  It will be  seen by the above representation (Fig.l7)that the pro-
portion of oxygen, which is the very  important element in the air,
occupies in  bulk about twenty-one  parts in the hundred,  or  a
IBBBBBBBBBBBBBBBBI IBB
    "BBBBBBBBBBBBBBB
      BBBBIIBBHBBBBBUB
      BBBBBBBBBBBBBBB
      ■■■BBBIIBBBBBBBB
      nzQlBBBBBBBBBBB
 
74          The Effects of Exercise on the System.

little more than one-fifth of the whole.  The other four-fifths being
mostly nitrogen. The use of this latter gas, the nitrogen, has scarcely
been determined;  it is thought by many to be merely a diluteut of
the oxygen to keep it under control, so that it shall not take fire
spontaneously, and burn everything up.
  So much for the air we breathe; the blood, of course, continues
the connection from the lungs to all parts of the body; and, let ua
examine that for a few moments.
  The beating of the pulse is the action of the heart in pumping
the blood from the  extremes of the body, and driving it through
                                the lungs to be aerated.  There
            Figure 18.             ar(3j on an average,  about sev-
 BBBBBBBBBBJBBBBBHBBBH  enty-two pulsations of the heart
 bSSSbShISbISSSSISSi  eveir mi*ute>and tw°ounces of
 SBlSBBBBBBBBBflSlaSSi  blood are  Passed thmUgh  the
 SbBBBBBBBBHBI IBBBBBB^  lungs at each pulsation, or from
 BBSBSHSSSSSBSSSSSSl  sixty-five  to  seventy  gallons
 SBbbIMBbBBbBBSbBbB  everv hour> and from fortF t0
  BBBBnlBBBBfll  IBHBH|  sixty barrels  per  day.   I  cle-
BBBBLf raw        IBBflBl  g.gned by ^ piece rf red flan.
^S^SSiiiy&lfaBHHHHUHIilBBiMB
                               nel (see cut, Fig.l8)to represent
the number of cubic feet of blood passed through the lungs every
twenty-four hours.
  We thus see the very large amounts of blood and air  that circu-
late through  the lungs, and can easily imagine of how much greater
importance the proper supply  of air is to the maintenance of good
health than the supply of food, because, while we eat less than two
pounds daily, we breathe fifteen times that amount, or about thirty
pounds.
  The  amounts here given are only approximations, they are sub-
ject to  extreme variations.
  We  all know the wonderful effect of any violent exercise, how
it sets the heart to beating, or, in other words, the blood to circu-
lating ;  this at once requires more air; we begin to breathe faster
and inhale and exhale much larger quantities.
  It is  astonishing how many persons disregard this wonderful pro-
vision of nature for keeping off disease, or for curing it after we
have, by our own negligence, allowed it to affect  our bodies.
  The simple difference in the amount of blood and air which circu-
late through our systems, under  different circumstances, shows us
what control we have over our bodies in this respect. 
                The best Way to Purify the Blood.           75

  The variation in this circulation from entire  repose to vigorous
action, may be thirty or forty per cent.—say thirty per cent.—taking
the average amount of air breathed at three hundred and sixty-
three feet, thirty per cent, of this would be near one hundred cubic
feet difference in the amount of the air breathed; and  taking fifty
barrels as the average amount of blood  circulated through the body,
thirty per cent, would be fifteen barrels.—Fifteen barrels  of blood!
coming to  the lungs to be purified, to be  aerated, and  one hun-
dred cubic feet of air, an amount thirty or forty times the bulk of
the body, and this the difference only,  not the actual amount, but
just the difference between a state of perfect quiet and that of active
exercise.
  What a means this is of influencing the condition of the body,
and what an incentive to active exertion instead of sluggish, stag-
nant quiet.
  Every child going to school ought to  walk  at least one mile in the
morning and the same  in the  evening in  returning  home;  and
no  child ought to see the inside  of  a school-house,  until quite
able  to walk  that  distance in  all kinds of weather, without  any
inconvenience.   This positive  necessity for daily exercise is  an
advantage, as  when it can be avoided  it is  frequently omitted in
stormy and unpleasant weather,  much  to the injury of the child's
health.
  It is quite a common idea with  many persons, that  if they feel
unwell  in  the spring of the year,  their  blood must be out of
order, it is impure.  Now there is but little doubt but the blood of
too many persons is very impure, but how do they  attempt to
purify it ?  Why by taking some vile  compound in  the  shape of
some patent pills, or other miserable stuff*.
  What would you do with a servant  that  would neglect to  put
coal on the fire, and just when she was  in a hurry to get breakfast
or dinner, finding the fire was nearly out, to make amends for  her
negligence, should pour turpentine or kerosine on, making a great
smoke and a temporary blaze ?  and probably, if a little careless in
its use, would  set the chimney on fire, and run much risk of burn-
ing the house  down.
  Well, now, it is just as reprehensible for you to go on all winter
neglecting to supply yourself with pure air,  and in the  spring find
yourself weak, debilitated with impure blood, and your fire nearly
out, and then to make amends for your carelessness, take some de- 
 76          Fresh Air best Medicine for  Wounds.

 testable pills or some of the world-renowned humbugs in the shape
 of patent tonics, that, according to the advertisements, are a certain
 cure for all diseases to which  " human flesh is heir."   And you
 might suppose from the reading of these advertisements, that they
 were an entire and perfect substitute for pure air.
   I  believe I never was quite so foolish as to take a bottle  of any
 such stuff;'but I think there must be a great many  who  do, from
 the splendid palaces that are constantly being built from the profits
 on the sales of such trash.
   You might, at first, suppose that  physicians, and  almost every
 one  else, would have  learned by  this time the best  cure for con-
 sumption ; yet how generally  you find persons with this disease
 shut up in close  rooms,  breathing very impure air,  and taking
 extra pains not to allow any draughts of any kind to enter the rooms.
   I  say, you would scarcely suppose it  possible that such a con-
 trary course should be pursued ; but we must remember how short
 a time it has been since physicians would not allow the patient to
 follow the dictates of  nature, and  drink cold water in fevers.
   And most of us remember how common it was, but a few short
 years ago, to take the very life-blood from a sick person, just at a
 time when it was most needed in carrying off the disease from the
 system.
   It is not in consumption alone,  that fresh air is of  such great im-
 portance, but it is in  all the diseases of the  human body.   You
 might, at first, think that  in amputating a limb ventilation would
 have nothing to do with the speedy recovery of the patient; this
notion, however, would be a great mistake, as ventilation has more
to do with it than any other thing.
   The surgeons, during our late war, were fully aware of this; they
well knew if they amputated a limb that the death or recovery of the
patient depended more upon the  air he breathed, than any other
agent with which they had to deal.
  I remember listening with much interest to the Surgeon General's
description of a very difficult  case of amputation, which he per-
formed in the  field in West Virginia.  He kept the patient with
him, (generally in a hospital tent,) and he was getting  along most
favorably; but was sent finally to one of the hospitals  in Baltimore,
which  I think was an old hotel; soon  after which he died.   I
heard the surgeons say afterwards that they scarcely could cut off
a finger in that hospital but the patient would die. 
*
                    Experiments with Flies.                  77

  They died from impure blood, they died for the want of ventila
tion, and this is simply the universal experience of every physician
and surgeon.
  If I were to scratch my finger, ventilation would have more to
do with its healing, than all the salves and plasters I could put on.
  It is a very common remark that a cut or wound will not  heal
because " the blood is out of order."  Very sensible remark, too, and
the quickest way to get the blood in order is  to breathe nothing
but pure air and plenty of it.
  You have often heard  of the woman that wanted some whiskey
for a spre toe, but on being remonstrated with  for drinking it right
down instead of using it to bathe the toe, remarked—" It will soon
get there."  She was not so far out of the way, either,  as we might
suppose at first; it would soon get there, indeed; and the inflamed
and poisoned  blood, I was going to say, would do almost as much
harm as it does when it  gets into the other end of the system ; but
perhaps that would hardly be possible.
  You cannot  live  without  breathing; you  cannot live without
eating; you cannot live well without exercise.  These are the three
grand essentials for health, comfort and happiness.
  The breathing is  of more than ten times  the importance that
eating is.   By breathing pure air you can digest  more food, and
you require more to satisfy hunger.
  Some of you may be  surprised to  hear me assert, that  if you
cannot get food you would die sooner by breathing pure air, than
you would by re-breathing  some of the foul poisonous air pre-
viously exhaled.  I was led to consider this question by the  very
unexpected results of some experiments  I tried last summer with
some flies.  I took six half-gallon jars, six quart jars,  and six pint
jars, making 18 in all, into all of  which I enticed flies by covering
the jar with bread, with a little molasses underneath it. I intended
to put two dozen into each jar, but they would not go in just to suit
me, so some had 20, some 40 and some 60.   Two of the bottles
of each size, making six in all, I filled with my breath, and sealed
up tight; two of each size I simply sealed tight, but filled with
pure air, and the other six, two of each size, I covered with coarse
netting, so as to allow of a free circulation of  air and keep the flies
confined.
   It was in summer, and I closed them up at  6 p. m., the sun about
an  hour high; I observed their condition at intervals of an hour, 

Those in Pure Air die First.
 making a note on each bottle.  At the end of the first hour those
 confined in the breath were  very stupid, many of them tumbling
 about from side to side, and  none able  to fly.  Those confined in
 the pure air were moderately lively, about half of them could fly
 from side to side, and were just as much at the bottom as at the top
 of the jar.  But a very different scene presented as the others with
 the circulating air were  examined; they were all crowded to  the
 fresh air opening, their feet sticking  up through the  netting, and
 there they remained with much persistence.   If driven away they
 would immediately return, and in one, there being more flies than
 room at the fresh air opening, they had to take turns standing at
 the window, which reminded me of what I observed  at Nashville
 jail, which was so shamefully crowded and with so little air, that
 each prisoner was allowed just so many minutes to stand  by the
 little hole that admitted  the fresh air, and this was considered  so
 great a privilege, each one waited  with the  greatest anxiety and
 impatience for his turn, and they would never miss, night or day.*
  So it seemed to be  a great privilege with  these flies, but I sup-
 pose they did not take their turn with so much punctuality.
  In two hours some of the flies in the breath seemed nearly dead;
 the others much the same.  At ten in the  evening no particular
 change.
  Next morning, at six o'clock, no marked difference;  those in the
breath a  little more stupid, and two or three  apparently dead; one
or two in the confined  pure air about dead, on  being put out in
 the bright morning  sun  they revived wonderfully;  those with the
 circulating fresh air kept  up a perfect  humming, and the others re-
 vived very much; but few, however,  of those in  the  breath, were
able to fly even with this extra stimulus.  At ten A. M., I went to
town, and at five P. M. returned home. I expected to find all those
in the breath dead, those  in the confined pure air about half dead,
and those in the circulating pure air as lively as  ever ; but to my
utter astonishment and disgust, I found every one of those in the
pure air stark dead—not  a vestige of life in a single fly.
  Those  in the pure  confined air were about  half  dead, and  nearly
the  same  proportion  of those confined in  the jar with the breath.
But they did not die  even in these with that perfect regularity that
I wanted them to do.
  * I should state, probably, that upon reporting  the condition of this jail to
General Rosecrans, then commanding, he had it remedied. 
Those in Foul Air Live ten times Longer.         79
  That is to say, where there were twenty in a pint jar, and twenty
in a quart jar, and twenty in a half-gallon jar, if those in the pint
jar died in twelve hours, I expected those in the quart jar to die in
twenty-four hours, and so on; but they did not observe any such
regular rules in dying.
  But, notwithstanding my great  disappointment, I kept the jars
and watched them.   Those in the breath died a little the fastest;
but very soon  after I noticed another form of animal life in the
shape of maggots, which soon attained the size of the original flies.
   Now, as these  bottles were perfectly clean  and corked air-tight
immediately after the  flies  entered, how did those maggots get
there ?
   Some of these flies lived ten days, (there would be but one or two
in a bottle that lingered so long,) the other animal life lingered some
three weeks.  These bottles, upon being opened, emitted a  horrid
stench.
   But the' bodies of the flies confined in the pure  circulating air
never had the least  unpleasant odor, were never touched by any
insect, and three  months after their bodies were just as bright and
clear as the day they died. Thus, those in the foul air lived ten times
as  long as those in the pure air. Now the practical lesson this teaches
is what I before  asserted, that when you breathe pure air you live
faster, so to speak; you are much more lively; you use much more
 exertion; but  all this exertion requires power, and, universally,
 power requires food.
   Now,  these flies in the circulating pure air no doubt used more
 exertiok  or did more work in the few hours they were living there
 without  food,  than  did those which lived ten days-their  bodies
 were so thoroughly used up, there was nothing but akin and bones
 left.
   This explains what might otherwise  seem a strong argument
 against breathing pure air.                #
    We find some poor, delicate creatures living on to be forty, fifty,
 sixty and even seventy years old, and appear  to be  a perfect re-
 futation of all regular physiological rules; but what sort of lives
 do they live ?  They cannot do a  quarter of a day's work, they can
 scarcely eat a quarter of a full ration, and if they  have existed to
 an old age they oft-times have scarcely done the work of a quarter
 of a lifetime.                               .              ..   ,
    And thus we find many poor people living in poor, unventilated 
 80          More Food Xeeded with Pure Air.

 houses, exist sometimes to quite an advanced age, but they are often
 sick and feeble.
   Therefore, when a person finds he cannot earn his living, or if he
 does earn it he is sure he cannot get sufficient food to eat, he had
 better imitate  the hybernating  animals as nearly as possible, and
 get into some close, unventilated  place and lie down in perfect
 quiet and repose—and not fret at all and he will then be able to get
 along on as little food as the most angelic of our fashionable belles
 could desire to boast of.
   On the contrary, when persons think they are able to earn therr
 own living  and a little more, the more pure air they breathe, pro-
 vided they have an abundance of good wholesome food and plenty
 of exercise,  the greater amount of physical or mental labor they can
 perform.
   The pecuniary value of  health  is but imperfectly understood.
 It was found in England that when a certain portion of the tenement
 houses belonging to some of the large factories were well ventilated,
 that the tenants required more food; it cost them more per week to
 live and supply themselves and families with the necessaries of life.
   They consequently could not work so cheaply from week to week
 as those living in un-ventilated houses.   This appeared  on its face
 to be a strong argument against the  pecuniary value of ventilation.
 But let us take a more careful view of this.  Every animal or ma-
 chine has its market value—a horse is worth so much in the mar-
 ket, so is an ox and a sheep, and to  our great shame we have until
 very lately had a regular market price for a man and a woman.
 Owing to even the little intelligenee which it was formerly ad-
 mitted that  a slaye had over a horse, we would give four or five
 times as much for a man as for a horse.
  A good  man before the war was worth  from twelve to fifteen
 hundred dollars, and some two thousand.
  The superior intelligence  and energy of any one  here, and the
 greatly enhanced prices since the war, in connection with the fact
 that one man with brains  can manage machinery that is sufficient
 to do the labor of twenty horses, adds greatly to the value of an
 mtelligent man,—or, in other words, any  manufacturer or capitalist
 would be very willing to give $5000 for the services for  life of any
 intelligent, able-bodied man  between the ages of twenty and thirty
years, taking all the risks of his living, and clothing and feeding him
 for life. 
National Health National Wealth.
81
  Now, that $5000 is the entire capital of many young men.  Sup.
pose a  large manufacturer wants hands at piece-work, and this
young man, say, is just married,  and anxious to get along, takes
the work just as low as he possibly can; he finds by saving a little
in his food, and by keeping  his house shut up tight, with an air-
tight coal stove he can save coal, and thus at the end of the week can
just make both ends meet, or, in other words, can pay expenses.
  Now he does not calculate how much of his original $5000 he
put into that work for the capitalist—but by  the reduction of his
physical strength he has used two shillings' worth a day of that capi-
tal ; twelve shillings a week, forty-eight shillings a month, and so on.
  Thus drop by  drop does that wealthy capitalist absorb the very
life blood.   Ounce  by  ounce are the sinews of this poor man bar-
tered away and appropriated by the capitalist.
  He is daily growing  weaker as his family cares  increase, and in
a  few years, with a wife and family  of small children entirely de-
pendent on his daily labor for their food, clothing and schooling, he
finds himself broken down in health with a ruined constitution, and
he is then cast aside for another, younger and more vigorous man,
who will engage to work cheaper, and can afford to do so by using
two shillings' worth daily of his $5000 capital  the same as  his pre-
decessor.
  This-arises from the ignorance of these  laboring  people of the
true value of health and of the proper means of preserving it. What
is  the result ?
  A nation of unhealthy people  must inevitably become a nation
of paupers,  but  a healthy nation will surely  become a wealthy
nation.
  For a proof of this assertion we have only to look to the manu-
facturing districts of England, as they are  amongst  the most un-
healthy.  Could  they support themselves if their trade with foreign
and newer countries was  cut off?  Undoubtedly not.  And look
at  New  England, what  does the census of her manufacturing states
give ?   A very small increase of population indeed.
  And the manufacturing wards of this city, too, will show a greater
amount of ill health and pauperism, which always go together, than
the non-manufacturing districts.
  Now, how can this be  remedied—by any simple act of legisla-
tion ?  I answer no!  Not even the fiat of our Congress,  rcpresent-
in«- as it  does,  the most powerful nation on the  face of  the earth, 
82
General Education Wanted.
could reconstruct society in this respect.  No, you must teach the
people, the laboring man, the bone and sinew of the  nation, the
value of health and how to preserve it.   The parents then will be
but in the prime of life when their children shall have grown to
manhood, and they in their turn will be competent to care for their
parents in old age.
  I want each of you to become a lecturer on ventilation; I do not
mean merely to  give three or four lectures in a whole year—but to
lecture every day  of your lives, because there is not one of you
here but what has some friend now suffering for the want of pure
air.
  I want  you  to  go  to  the  home of the laborer, the man that
is not here to-night—he whose laborious toil from morn to  eve
demands rest in the evening, instead of allowing him the privilege
of attending lectures.
  I have  visited many such, and find  that a few  simple, kindly
words of explanation are always gladly received, and frequently
have their good effect in inducing them to remove a fire-board in
a sick-room, or by putting on an extra blanket, to allow the win-
dows to be opened a little more  every  night,  and thus do a real
service to these poor, worthy people, by getting two cubic feet of
pure air to enter, where but one entered before.
  Could Philadelphians but be fully aroused  to the great import-
ance of this thing, the mortality of this beautiful  city might be
reduced for the year 1868, perhaps even more than it  was for the
year  1867, because I believe there is no city on the face of the
earth so favorably situated for  an immediate  reformation in this
respect as  this  city, as all the  houses are built so isolated, with a
window and fire-place in  nearly every room: while  in  New  York
one-half of the population live in houses of entirely different con-
struction, nearly half the sleeping-rooms being merely dark closets
into which the purifying rays of the sun and the pure external air
can never enter.
  And this is  a  very serious  defect, which nothing but tearing
down and re-building can fully remedy;  although a good artificial
ventilation might  greatly improve them.   Philadelphia  has  the
advantage in this respect, very decidedly.
  If it were in any way possible to get all the physicians stirred
up, to make some active exertions towards inducing the people to 
Philadelphia Physicians slovj to Adept 2s ew Things.    83
be more careful about the ventilation of their houses, it might have
a wonderful effect.
  This, however, is hardly to be hoped for, as a regular old school
Philadelphia physician is probably about as respectable and proper
and conservative a man as  the sun shines on.  We  could  scarcely
find a greater curiosity than the name of a regular old school Phi-
ladelphia physician at  the head of a recommendation to public
favor of any new thing, no matter of how much public utility it
might be.
   The surgeons in charge of the splendid  hospitals  built in and
 around Philadelphia during our late war, made verbal and written
 protests against having these hospitals ventilated in winter, because
 the form adopted by the Government was a  little varied (for the
 purpose of adapting it especially to these temporary buildings)
 from the time-honored  forms to  which they had been accustomed
 from their childhood up.  There is one great comfort to you in this
 characteristic of your regular  physicians :—if your doctor was  to
 offer you a medicine you were not accustomed to,  do not have the
 slightest hesitation in taking it, for you may rest perfectly assured
 that  it has been tried'in every hospital in the  land, and that it is m
 common use in every other city in tie Union before it is  offered to you,
   It seems to  me a little unfortunate  that  our physicians have
 fallen into this quiet, easy way of gliding around so elegantly, with
 their hands in  their  gloves  and their brains in their  medicine
 boxes.  Now, this is not because these physicians  do not really
 know better, because, if you were to attend their lectures you would
 find them discoursing  very eloquently on the great importance of
 the functions of respiration, and the importance of pure  air in all cases.
   Note.—If you  should happen  to find the Professor  lecturing
 thus in  a close, unventilated room, smelling very badly,  this, you
 must remember, is a strong argument of their appreciation of pure
 air--as you know doctors never take their own medicine.
   Or if you were to go into the  office of any one of them, and take
 up any of the standard text books on their tables, you will find that
 all eminent medical writers lay very great stress upon the necessity
 for the most perfect  ventilation  at all times.   They  consider it  of
 greater  importance than eating, drinking and medicine in the pre-
 vention and cure of disease.  For instance,  here is Carpenter s Hu-
 man Physiology, which, in summing up a very elaborate  article on
 Respiration, says, page 326 : 
 84           Extreictsfrom  Carpenter s Physiology.

  "Thusit appears that in all climates, and under all conditions of
 life, the purity of the atmosphere habitually respired is  essential to
 the maintenance of that power of resisting disease which, even more
 than the ordinary state of health, is a measure of the real vigor of
 the system.   For,  owing to the extraordinary capability which the
 human body possesses of accommodating itself to circumstances, it
 not unfrequently happens that individuals continue for years to
 breathe a  most unwholesome atmosphere without apparently suf-
 fering from it, and thus when they at last succumb to some epi-
 demic disease, their death is attributed solely to the latter, the pre-
 vious preparation of their bodies for the reception and development
 of the zymotic poison being  altogether overlooked.
  "It is impossible, however, for  any one  who carefully examines
 the evidence, to hesitate for  a moment in the  conclusion that the
 fatality of epidemics is  almost invariably in  precise proportion  to
the degree in which an impure  atmosphere has been habitually re-
 spired,  *  *  *   and that by due attention to the various means
of promoting atmospheric purity, and  especially efficient ventilation
and sewerage, the rate of mortality may be enormously decreased,
the amount and severity of sickness  lowered in  at  least an  equal
proportion, and the fatality of epidemics almost completely annihi-
lated.  And it cannot be too  strongly borne in mind, that the effi-
 cacy of such preventive measures has been most fully substantiated
 in regard to many of the  very  diseases  in which the  curative
 power of medical treatment  has seemed most doubtful, as, for ex-
 ample, in cholera and malignant fevers.
  " The practical importance of this subject may be estimated from
 the startling fact, which inquiries  prosecuted under the  direction of
 the Board of Health have recently brought to light, viz : that the
 difference in the annual rates of mortality between the most healthy
and the most unhealthy localities in England, amounting to no less
than 34 in 1000. is almost entirely due to  zymotic diseases, which
might be nearly (if not  completely)  exterminated by well-devised
sanitary arrangements.   The lowest actual mortality is 11 per 1000,
while the highest is 45 per 1000, and  between these extremes there
is every intermediate degree of range.   But what  may be termed
the inevitable mortality, arising  from  diseases which would not be
directly affected by sanitary improvements—is a  nearly constant
 quantity throughout, namely, the 11 per 1000  of  those districts
 which are free from zymotic diseases. 
           Half the Deaths Preventable by Ventilation.       85

   " The average mortality of all  England, in ordinary years, is
 about 22 per 1000, or just double that to which it might be reduced;
 bo that  taking the population of England and Wales (as by the last
 census) at nearly 18,000,000, the average annual mortality must be
 396,000, of which only 198,000 is inevitable, an equal amount being
 preventable."
   Thus you see these physicians tell you that one-half of all  the
 sickness and death are " preventable."  They don't say they can cure
 them with their medicines, but that they are preventable, and that
 the great means they recommend for accomplishing this wonderful
 work is pure air—ventilation.  But, although they have said this
 and re-said it, for the last fifty years, yet it has seemed, as Dr. Ham-
 ilton has said, a herculean task to make the public  at large  com-
 prehend it.   So that a  whole life spent  in teaching the value  of
 pure air has seemed to be a whole life almost wasted.
   The  extracts that I have just read were written more than  ten
 years ago.  But the very  careful investigations that  have been
 since conducted by many able and scientific hygienists, only more
 fully prove these assertions.  Perhaps  no city presents a stronger
 contrast between her healthy and unhealthy wards  than does the
 city of  New York.
   Dr. Harris says of one of the most  densely populated wards of
 New  York, the Seventeenth, that the death rate has been for several
 years less than 17 to the 1000,  and even during the terrible heat of
 July, ^G6, the  uniform low mortality of that ward was scarcely
 affected.  The death rate in this ward, with  its 27,000 inhabitants,
 was,  during  the  six months  ending  October 1st, (including the
 cholera summer) only 16^ to  the 1000.  In the  same period the
 mortality in the notoriously foul  Sixth Ward was 54 to the 1000.
 And although the death rate of Philadelphia is exceedingly favor-
 able, by comparison with some other cities, as, for instance, New
 York, where it is about 30  to 33, while in Philadelphia it was but
 20  deaths to the 1000 of population, yet,  you  see even  that is
nearly double what it should be—that it would only be 11 per thou-
sand if we could only avoid those zymotic diseases, or such as are
caused exclusively by foul air poisons.
  And I believe with an extra ton of coal for each family, and an extra
 blanket for each bed, so that every chamber window might be open-
 ed, this  night, the one-quarter of one inch, to-morrow night two-quar-
ters, and the next night three-quarters, and so on until every cham- 
S6 The Advice of a Good Physician better than Quack Medicines.

ber could be kept the whole night in a pure and  wholesome con-
dition, and never after closed, we could do much towards  saving
the 6000  or 7000 lives due to this proper  death rate of 11  to the
1000.
  But now I have a word to say to you, the people that employ
these physicians.  They have a good deal of human nature about
them after all—they are not so very different from  the  people
amongst  whom they  live and by  whom they are employed.  I
don't suppose there is a city in the United States in which a phy-
sician has to  be more exceedingly careful of his reputation  than
in this very city of  Philadelphia.  And I happen to know some-
thing of the reasons for omitting to prescribe, more frequently, fresh
air as the medicine most needed for their patients.   How many of
you, if, being sick, were to have a physician to call frequently, and
just say  to you,  " All  you need is more fresh  air,"  would not
say, in your mind (if not out of it), " Well, I think I can attend to
getting a  little fresh air myself, without paying  that doctor two
dollars per day for telling me that, and I think, upon the whole, I
will get some doctor that will do something for me."  So you will
probably send for some man you have heard of, as having made
wonderful cures of some friends, and if he should happen to be a
regular shrewd  humbug, he  would  make a wonderful  account of
your disease, and finally tell you he  thought he had something that
would just suit your  case, and, as  before illustrated, would com-
mence pouring turpentine or kerosene oil  on your fires, by which
he would create a great smoke and temporary blaze, and this would
induce you to exclaim, " What a wonderful man!  he does some-
thing ;" and if he could get  you out into  the fresh air, that would
soon cure you, perhaps, while you would be giving all the credit to
his medicine, and the dollars to him for his trash.
  I know some physicians, of most excellent good common sense,
who have ideas of their own, and independence enough to express
them, and have much more  faith in good hygienic rules and regu-
lations, who prescribe pure air, pure water, good wholesome food,
and plenty of exercise, but seldom prescribe medicine.  These men
would have to beg their bread if they had to depend  exclusively on
popular custom for their living.
  And now let us take a new start.  Let us put our shoulders to
the wheel manfully.  We have made a most excellent beginning
during the year 1867, and  our  journalists, too, could they be 
             Journalists could help the Good Cause.          87

induced to give a line or two every day for some good hints as to
the value of, and the best means of obtaining pure air, such results
might be obtained as would astonish the world, and  would give
one of the grandest examples of hygienic reformation ever recorded.
6 
LECTURE II.
  The air we breathe—what is it?   Oxygen and nitrogen, the
young student will promptly answer.  Oxygen and nitrogen cer-
tainly ; but how many of us really comprehend what these ele-
ments are ?
  We are told that the distance around the earth is so many thou-
sand miles, and so many more to the sun, and that the nearest fixed
star is a great many millions of miles from us;  but  it is no matter
how many (though the astronomers have stated it all with  accu-
racy), for I believe it  is entirely impossible for the mind of man
to realize, or in any way to imagine, more than  an exceedingly
small fraction of that  distance.   His imagination will, I think, in
all such attempts, be very much limited by the greatest distance he
may at some time have seen with his natural eyes.
  And when the microscopist tells us  of the immense number of
living beings  found in a  drop of water, and when we must know
that these diminutive creatures necessarily possess—for performing
their functions of life—much of the  exquisite machinery of the
larger animals, how  entirely incapable are  we of extending Our
imaginations to any satisfactory apprehension of the minuteness of
these things.
  Thus, in whichever way we may turn our investigations, we can
find no limit to the minuteness on the one hand, nor to the great-
ness of creation on the other.
  Were we to attempt the study of a single blade of grass, and en-
deavor  to learn the many combinations  of the simple  materials
constantly surrounding  us which enter into its composition; or
were we to try to comprehend the power of that  wonderful sub- 
Intelligent Persons occupy Foul Rooms.         89
stance we call heal, its source, and the cause of its  undiminished
supply, we should find it the study of a lifetime.
  Some of the experiments we may show you this  evening, may
be as familiar to you as the reflection of your own face in the glass,
yet they may appear to you in a new combination, and possibly sug-
gest to you some new thoughts.
  You may have attended a lecture on Chemistry only last night,
and have been delighted with the most  beautiful and  elegant dis-
course on the all-powerful and wonderful properties of that greatest
of substances—Oxygen—and have  seen with  what  ease  it could
build  up and  pull  down all  earthly things  that  man  beholds.
Or you may have followed the Geologist  in  his deep  and profound
researches into the very bowels of the earth, and listened with rap-
ture as he explained the wonderful formations and transformations
which these same substances have been undergoing for  untold ages.
Or perhaps  you may have attempted to follow the Astronomer in
his daring flights of fancy, as he endeavored to  explain to you how
that wonderful heat and light of the sun are  kept up by  the millions
upon  millions of  meteors, which, drawn  irresistibly from their
paths, dash headlong into that great consuming fire.
  But this evening, let us concentrate our  thoughts much  nearer
home; let us endeavor to comprehend more fully the most inte-
resting to us of all these mysterious changes; I mean that change
which is produced in our own bodies  twenty times every moment
of our lives, by the air we breathe.
  I am led to believe that we have  not  more fully comprehended
this mysterious transformation thus going on within our own bodies,
than we  have truly measured mentally the  distances to the fixed
stars, or  the number of days and hours since the formation of the
earth, or can compass  by our  limited  reasoning, those powerful
influences which have caused the sun  to send forth heat and light
without measure, for unnumbered ages, and yet the source itself to
be undiminished still.
  I say,  I am led to the belief of this general  want  of knowledge
upon this subject, by noticing daily, and almost every  hour of the
day, the  most intelligent  and  best  educated men and  women
amongst  us, so entirely ignoring the effect designed by  our Creator
to be  produced by this constant  breathing of pure and fresh oxygen
and nitrogen, as to shut themselves  up in close rooms,  and breathe 
90                 Composition of the Air.

and re-breathe the same  air, till it becomes  excessively foul and
poisonous.
  There is no  standard  of taste  respecting things seen.   Those
which we know produce  the most comfort, and give  us the most
happiness, no matter what may be their form, we consider the most
beautiful.
  We cannot see pure air, and therefore we  can  scarcely call  it
"beautiful;" but let us hope that we may so cultivate the imagin-
ation, that if we can but  comprehend,  even in  a slight degree, the
marvellous effect that it  produces on all  that is human, we  may
soon learn to feel that  pure air was not only among the greatest,
but that it was  the greatest of all  the Creator's  temporal blessings
to his creature, man.
  At our last lecture, I endeavored to  impress upon your minds,
the ver}T large amount of air which was breathed by each individual
every twenty-four hours,  it being about 350 cubic feet, or 125 times
our own bulk.
  Now,  if all this great bulk was  simply nothing, or  possessed no
qualities except what we  could discern with our ordinary vision, it
might be of little value.  Our eyes are the great medium through
which we receive information; but, as  I said before, we cannot see
the atmosphere, and so I fear many of us fail to appreciate the true
value of pure air  on this account. We are  obliged,  therefore, to
explain  its peculiarities in a secondary manner, by producing some
effect that may be seen.
  The air we breathe is composed  of seventy-nine parts  by bulk of
nitrogen, and twenty-one parts of oxygen.
  The oxygen is the busy body ; it is the hard working,  active sub-
stance that  keeps up the fires, cooks the food,  burns  up the trash,
purifies  the blood and turns it from a dark purple to a bright crim-
son color.
  [Here followed the ordinary experiments of burning sulphur and
phosphorus in  oxygen, those  elements being consumed with great
rapidity and brilliancy.]   Thus you see some of the effects that may
be produced with pure oxygen, which forms about one-fifth of the
air, when it is separated from  the nitrogen forming  the other four-
fifths  of the ordinary atmosphere.  The  nitrogen  seems to be a
mere dilutent to keep the oxygen  under control, and to  prevent it
from burning or destroying everything by fire or rust. 
              Experiments with a Burning Candle.           91

   [A second experiment was here introduced, to show the indis-
pensability of oxygen, and was explained as follows:]
   Here we have  an ordinary candle, which you see burns just as
candles generally do; but now let us place it under this small bell
glass  receiver (a), and observe how rapidly the flame diminishes in
size.
   This next glass jar (b), contains lime water, or if it should chance
to be  Goulard's Extract of Lead, it would answer the same purpose ;
and you will please notice that it is at present perfectly transparent.
   From the  top  of this wash-bottle we have a connecting tube
passing down under and extending up again to the top of this glass
jar (c), which is now filled with water.
   You  see the candle  is now almost entirely extinguished, but
please note carefully as I open the stop-cock (d), how quickly the
                             Fig. 19.
candle gets brighter;  and you see also the air bubbling up through
the lime water, and in the glass receiver the water gradually falling
as the air is admitted  to take its place.
   The candle is now burning as brightly as though it were in the
open air; it has all the oxygen it wants, but  let me turn the stop-
cock so as nearly to close the current of air, the velocity of which
you can measure by the bubbling up of the air through the lime-
water.  See now how the flame of the candle has diminished! Did
you ever see such a beautiful way of regulating the burning of a
candle ?   We thus have  as perfect control over it as we have over
the gas-light.  You will  notice that the entire  bottom of the bell
glass is  open, and don't  forget that when you  are burning  much
gas, you  must have—as this experiment teaches—an outlet for the 
92                 Consumption of Oxygen.
escape of foul air from the top of the room.  The open fire-place
so useful for ventilation during the day, is not sufficient when the
gas is lighted.
  Ah! see what a change has taken place in this lime-water; it has
become  white and milky ;  also,  the water has  fallen out of the
glass jar, as you see, and drawn in sufficient air to take its place.
  Now,  we are anxious to  know what change has taken  place in
this air.   The milky appearance of the lime-water is the chemist's
test of carbonic acid;  we will therefore assume that that has been
caught there, and, as the air  has thus been purified again, looks
very  pure, as seen under the gas-lightj at any rate.  Let us see
now if the candle will  not burn just as brightly  as in the open air.
  Why what can be the matter?   It goes out as suddenly as if it
were dropped  into the water.  And for what reason?  It is simply
because  the oxygen is  all  burned out, and there  is nothing but the
nitrogen left,  and that is entirely incapable of supporting combus-
tion.  By looking at this candle, you see we have scarcely burned
the little cone at the top, and  yet even that has produced sufficient
carbonic acid to discolor this bottle of lime-water, and burn all the
oxygen  out of the large jar of air so  thoroughly that it will no
longer support the flame of a candle.  An ordinary gas-burner con-
sumes as much oxygen and forms as much carbonic acid as five
persons.
  Now let us see how nearly the burning of the fires in our bodies
correspond with that of the candle we have just examined.
  First  let us take another bottle of lime-water similar to the one
we have just  used, and by inhaling through the short tube, I draw
the atmospheric air through the  lime-water; but, as you perceive,
although I have inhaled many times, there is no discoloration of
the contents.   I fear, however, if I was to continue much longer
drawing the  air from  this (as I must confess) unventilated room,
with all these gas-lights, as well as human fires burning, I would
soon produce  an evident discoloration; but I will reverse the pre-
ceding operation and force my breath  through the long tube, and
you now see how quickly that causes  the  same milky appearance
which resulted from the air coming from the candle.
  Let us proceed now to  detach  this tube, and  by drawing the
air  out  of  the glass  receiver (c),  the water flows in to take its
place.   Now we  will  notice  the  number of  exhalations  re-
quired to  drive  that water out and fill the jar with my breath 
Cold Air better than Warm for Breathing.        93
and  likewise the number  of seconds.   There, you see  it has
taken  nine exhalations, and required  thirty-two seconds,  and
that  jar, as I know, holds  six quarts,  or one  and a half gallons,
which would be represented by 346 cubic inches.  This is quite
excessive breathing, as it would  be at  the rate of over  600 cubic
inches per minute, and you remember we found only 400 the other
evening as the average; it may not, therefore, show the ordinary
signs of pollution, but let us try it  with a candle.  Ah! you see it
is too foul altogether to support the combustion of a candle.
  I wish I could tell you something about the composition of that
jar of air ;  but really, I know nothing about it as I ought to know,
nor does any one else.  The doctors tell us that one-half of all who
die are killed by foul air ; but I believe there  is not a medical col-
lege in the whole countcy that pretends to teach the careful analysis
of this, said air. They will spend month after month discussing,
and  write volume upon volume  to  prove, that the ten-thousandth
part of one drop of  medicine will have more effect than a whole
spoonful; but as to teaching the analysis of anything quite so com-
mon as the air we breathe, that would be too commonplace entirely;
so I must simply repeat, we know nothing about  it.   But there
have been a few Germans and  Swiss, and some others,  who have
been able  to tear themselves away from the  fascinating study of
medicine, long enough to make  a few preliminary experiments on
the* more urgently important subject of the air we breathe, and to
endeavor to ascertain the effect of the air upon the body, and, recip-
rocally, of the body upon the air.
  From the crude facts that have been thus gathered, we  are led
to  suppose that the proportion of carbonic  acid in  the  exhaled
breath, varies greatly under  many different circumstances.
  Temperature  has a very great  effect.  Experiments  have been
tried with birds and animals, showing that there is less than one-
half exhaled when breathing a temperature of from 86° to 106° than
there  is when  breathing air at a temperature near the freezing
point.
  The  proportion of carbonic acid contained in the exhaled air
varies greatly, as does  also  the aggregate amount; it  constitutes
from 3 to 8 per cent, of the volume exhaled—probably 4 or 5 per
cent, would be the proper average.   Hence, as pure air (so  called),
seldom contains more than five parts of the gas in ten thousand,  it 
94    Twenty-five Cubic Feet of Air per Minute Required.

follows that the breath contains one  hundred times  the  natural
quantity found in the atmosphere.
  That jar, therefore, contains about one hundred times as much
of this poisonous  deadly gas,  as does pure air, and not only that,
there are particles  of my body, there are portions of my brain (I
don't mean in the sense in which we use it to express the result of
thought), but I mean the actual worn out material; and the only
valuable substance it originally contained—the oxygen—has been
taken out.  It is upon  the whole a very disgusting mass, as you
must admit, and we will remove it carefully, so as not  to permit it
to escape into this room.  I perceive you seem a little amused.   I
suppose it is at the idea of carrying out that one jar of foul air such
as we are all the time exhaling into  the same air we inhale from ;
but I think this gives you the true idea of ventilation.
  The actual amount of air breathed is comparatively  very small;
it is  only about the one-fourth of one cubic foot per minute.  But it'
is the contamination of the remaining mass that causes the trouble.
For instance, as the exhaled breath contains one hundred times as
much carbonic acid as pure air does, hence, if one cubic  foot of
breath was diffused through one hundred cubic feet of air, it would
add,  even to that very large amount, nearly double its  normal
quantity.
  In determining what amount of fresh air  must be supplied for
each individual, in a room in which  we are each breathing into and
from the same general mass, it becomes a question of what  propor-
tion  of other persons' breath we are willing to take  into our own
lungs.  If we breathe but the one-fourth of one foot per minute, a
supply of twenty-five cubic feet per  minute would give us one hun-
dred times the actual amount  of air that passes through the lungs,
so that we should then only have to  breathe double the  normal
quantity of carbonic acid.
  This twenty-five feet per person per minute, however, is consid-
ered by many a large  allowance.  As low  as ten cubic feet per
minute for each person is considered by others to be a sufficient
quantity, yet even that is  much more than vast numbers of our
buildings  are supplied with,  as may be  readily judged from  the
disgusting foul odors  noticed  in many of them, and which could
scarcely ever be perceived if this small allowance even was care-
fully furnished.   Of excretions from the surface of the body in the 
Uniform Temperature of the Body.           95
form of insensible perspiration, which are constantly occurring, I
have as yet made no allusion.
  But now suppose that instead of discharging the breath into the
general reservoir, we could discharge it  into a closed vessel, as we
have done, or by a speaking tube—if I might so term it—or better, a
breathing tube, directly into a foul air duct, to be carried entirely
out of  the building; don't you see that  one-tenth part  of the air
that would otherwise be required, would in that case be entirely
sufficient?   It  would then be  certainly much  preferable  to  our
present arrangements, because we should have radically pure  air,
instead  of at best, that which was slightly contaminated.
  I don't exactly mean to advise that we should each one carry a
long breathing tube in his pocket, and the moment he  came into
the house, place one end in the fire-place, and put the other in his
mouth before he began to talk to you; but I think it demonstrates
the true principle upon which we should act, in making our arrange-
ments for ventilation, which is  to say—to confine the polluted air—■
and to  remove it as soon as possible from  the room.  I design
showing you in a subsequent lecture that this has been  my guide,
in the arrangements for ventilations in hospitals, churches, schools,
etc., and which, I may  add, have been very successful.
  It is a curiously interesting fact, that the temperature of the body
remains nearly uniform at 98°, under the  most extreme variations
of external temperature, say from 40° to 60°, below zero, as expe-
rienced by Arctic voyagers, to  a temperature of from  200° to 300°
above, experienced by persons accustomed to entering and remaining
for some  time in furnaces for baking  certain wares, and  in like
employments.
   The cooling off, when we are very warm, is caused by the vapori-'
zation of  the perspiration.  A pint of water makes 1700 pints  of
steam, but as it turns into vapor, or is enlarged like the expansion
of a sponge, it absorbs heat very rapidly.   Thus, when you  per-
spire freely, or when you see the vapor arising from a hard-worked
animal, you may know  that  the heat  is being conducted away
rapidly.  It is for this reason that the drinking of a cup of hot tea
on a warm summer day, by inducing profuse perspiration, has such
a cooling and refreshing effect.
   But this very fact of profuse perspiration is frequently the cause
of what we term  " colds;" because, when we are perspiring thus
freely from active exercise, and the heat  is escaping very  rapidly 
96
Danger of " Cooling off"  Rapidly.
 from the body, we are apt, when we have an opportunity to rest, to
 indulge in the agreeable process of "cooling off," wherein the tern.
 perature of the body is reduced so  much more rapidly than in its
 ordinary conditions, that  almost before we are  aware, it is quite
 below the usual temperature of health.  And so it happens that the
 relaxation of the respiratory organs, and the cessation of the rapid
 flow of blood, prevents the quick renewal of the heat; or in other
 words, the fires having been put out by the profuse perspiration, it
 requires a long time for them to be rekindled, and to get to burning
 again freely.
   There are said to be 2800 little tubes for the escape of the per-
 spiration, in every square  inch of one's body, and that the  united
 length of all those in the skin of a single person, is about twenty-
 eight miles;  so that the length  of those in two persons would reach
 from here nearly to the Atlantic Ocean.  Now, the little valves at
 the outer ends  of these tubes, close very quickly  on being exposed
 to the  cold.  But as the flow of the current from the interior of the
 body, does not  feel  the effect of the cold as suddenly as the  valves,
 it will continue to press forward with its load of impurities, until,
 being checked from escaping, it  will be dammed  up near the ordi-
 nary places of exit,  causing a pressure or inflammation.
   To show what powerful effects may be looked for by this  sudden
 stoppage of perspiration, we need only to adduce  the fact  of  the
 large amounts of moisture which may be  driven  from the body
 through the medium of these channels of the skin.  A number of
 experiments tried by Dr. Stouthwood Smith, on the men working in
 the Phoenix Gas  Works, showed that the  average loss of  weight
 per man while charging the furnace or during an exercise of about
 fifty minutes, was something like three  pounds.   Just think what
 an inflammatory effect this enormous pressure, this sudden restrain-
 ing of the great flow of impure moisture, must produce!
   And it is not on the external surface only,  that this result is pro-
 duced,  but the lining membrane of the air-passages  to the lungs is
 affected even more suddenly, and is also  more sensitive than  any
 other.   Therefore, we should always remember  that the moment
we diminish any active  exercise, we should immediately, even-
while much heated, put on  an  additional garment, or otherwise
provide for a very gradual cooling off; being careful that we first
cool off internally, before allowing the temperature  of the external
surface to be much lowered. 
"Taking Cold" on Leaving a Foul Room.       97
  The manner of taking cold on leaving a crowded and badly ven-
tilated room, is quite different.
  You remember the experiment with the flies that lived ten times
as long in the foul  air we breathe, as did those in the pure air, and
which we attributed to the very sluggish action of all their living
functions.  Now, when you leave a hot, foul room, although your
perspiratory glands may be fully open, and  there may be a rapid
vaporization from  the surface of the body and the air-passages to
the lungs, which would not be caused by exercise in this case, but,
worse, by the heat of  the room, yet the vitiated air that you have
been breathing, has not only choked up your lungs and filled your
body with the actual presence of much poisonous material, but it
has so reduced the circulation that you cannot get up a reaction.
   As in one minute after you have emerged into the pure air, you
have breathed twenty times, or inhaled 400 cubic inches, the lungs
therefore, are the parts most quickly affected.  You will frequently
feel the inflammation thus produced in your throat, in five or ten
minutes after leaving such a room; but you must remember that
in ten minutes  you will have breathed 4000 cubic inches of cold
air.   To leave a room  such as I have  spoken of, and, in place ol
walking, to sit down in a cold, crowded, foul car, with your back
towards  the window, is one of the very best possible means, not
only  of taking cold, but of contracting any other disease to which
you may possibly be subject.
   The phenomena of  a  burning lamp or  candle is a  beautiful
emblem  of human life.  By way of illustrating this part of my
subject, I have here a  common coal-oil lamp with glass chimney
attachment; having  lighted which, I will  paste  a piece of paper
over  these openings at the base, intended as  entrance passages to
the air.  The evil  result of this operation is visible at once; the
flame looks bleared and it smokes most miserably; that lamp, to
all appearances, has certainly got the dyspepsia 1
   The food that feeds that flame is simply undigested for the want
of pure air—for the want of oxygen—in other words, for lack of
ventilation.
   Similarly, when you eat your full allowance of food, and do not
breathe sufficient  pure air to  warm and purify your blood, your
whole system becomes filled with undigested carbon or " smoke," as
we may call it, the same  as  with that  lamp.   Likewise  the same 
98         How to Destroy or Preserve  Good Jleattn.

amount of food will be of less than half  its value; just as that oil
gives less than half its full light.
  One most excellent  way to fill your system with smoke, and de-
stroy half your usefulness, is as follows:  get up late in the morning,
eat a hurried breakfast, and immediately rush to the cars.  Sit
half or three-quarters  of an hour in the close, foul car, and if your
feet get thoroughly chilled, all the better for that purpose ; a pair
of tight boots is the proper thing to prevent the  natural circulation
of the blood. Have a care to sit with your back to the open win-
dow, and your face towards the centre  of the foul car; that, too,
helps.   Your breakfast most probably may not have digested well,
and if you feel pretty  miserable in about two or three hours, you
should  commence eating  ground-nuts,  and  keep on  at irregular
intervals until lunch-time.  At this happy period, if you are  still a
" little under the weather," and not very hungry, go  to the restau-
rant, and eat merely a piece or two o£ "home-made pie? with a glass
of milk, nothing  more, and I should think that would be  about
sufficient to keep  you  up to the American standard of the shameful
abuse of health.  If  there should be anything  wanting, however,
you might accept  an invitation to a party, and after spending several
hours in a hot, unventilated room, of course you  would be too much
fatigued to  walk home—-in fact your thin-soled shoes and light
party-dress  won't admit of it—and  home you  ride  in a car con-
ditioned as regards wholesomeness and temperature, as aforesaid.
  You  may not  see at  once what connection these physiological
explanations have with ventilation;  but  it is the severest tax upon
my ingenuity, so  to warm and ventilate  a room  or car, as fully to
meet these imperative demands of the physiologist.
  Let me say in a few words,  always keep your  feet warmer than
your head, and your back warmer than your face.  I will not say
now, turn your back  to your enemy, but I will say, never turn
your back to your best friend.   Eat  heartily twice in  twenty-four
hours (never more than three  timev>)  of good wholesome food, and
always after eating sit down for a half or three-quarters of an hour.
Remain perfectly  quiet in a room ten degrees hotter than  the ordi-
nary temperature of that room, keeping the feet warm, dry and free
from pressure, and the back thoroughly protected from draughts,
with a cool fresh breeze blowing in your face. Follow this up care-
fully, for awhile,  and you will not say you cannot afford  the time
to spend thus, but you will say you cannot afford to omit it. 
Diffusion of Gases.
99
  We have here an arrangement by which we wish to explain in a
manner the diffusion of gases;  it has been furnished  me by Prof.
Albert Leeds, to whom I may say here, I have been much indebted
for collateral information and assistance in these lectures.
                 It is often remarked that one gas is a vacuum for
     Fie 20     another gas.  This is hardly the proper way of ex-
               pressing it, because that would  seem to imply that
               a cubic foot of carbonic acid gas would be diffused
               into a, cubic foot of hydrogen gas, both occupying
               the one space with the original foot of the latter;
               but this is not the case.  They become mixed, how-
               ever, by exchanging places.  For instance,  if we
               take a glass vessel, just one foot square,  contain-
               ing, consequently, one cubic foot of  hydrogen gas,
               which would weigh thirty-s;x grains, and place it
               over a similar vessel, containing one cubic foot of
carbonic acid, which would weigh 815 grains, or more than twenty-
two times as much as the hydrogen, the heavy carbonic acid  gas
would rise up into the vessel above, and an equal volume of the
light hydrogen gas would fall into the vessel below,  so that they
would soon become equally diffused.
  The apparatus which we have here for illustrating this beautiful
phenomenon, consists of a  glass tube, with  its lower  end dipping
into  a vessel of liquid (crimson-colored, so  as  to allow its move-
ments to be readily seen), and over the  top is placed and sealed in
position, an unglazed clay jar.  Now, into the glass bell-jar which
I hold, mouth downwards, we will allow a supply of hydrogen gas
to enter, which, as it is about fifteen times  lighter than the  air in
this room, it will  readily do, rising directly to the top, and displac-
ing the air.  The vessel being filled, as  I judge,  I will place it over
the unglazed jar, and at once you see the air, as it is expelled from
the bottom of the tube, bubbling up through the liquid in the re-
servoir.  This is caused simply by the hydrogen gas rushing through
that porous clay cylinder, and displacing an equal amount of the air.
  But  now we will reverse the operation.  We  will remove the
glass vessel previously filled with hydrogen gas,  and  then, as  the
porous cylinder will contain a greater proportion of hydrogen than
the surrounding  air, the excess of  the  gas will rush back again.
This result you see palpably and beautifully demonstrated by the
 
100   Not so Important Practically as often Considered.

rising of the crimson fluid in the tube, and its coursing around the
spirals.
  Now, this law of the diffusion of gases, is a vitally important one.
Did they not possess this property, the different gases would envelope
the earth in distinct and separate belts or layers.  The poisonous car-
bonic acid gas being formed in a great miasm near the ground, and
being fifteen times heavier than atmospheric air, would cover, pri-
marily,  the surface of the earth; then would come  a layer of oxy-
gen, next a layer of nitrogen, and so  on. Nor would heating them,
even supposing the  heat should be applied at the bottom, be suffi-
cient to mix them thoroughly, because each density, it would  be
found, would circulate nearly horizontally by itself.
  Hence, it is evident  that this becomes an important question with
reference to the subject of ventilation; for the reason that, in a still
room, although the breath may at first fall to the floor, owing to its
having a hundred times as much carbonic acid as ordinary air, yet
that would soon be diffused through  the whole  room.  And yet I
do not pay so much attention to this,  because I think the supply of
air ought to be so rapid and abundant, that the slow process of the
diffusion of gas would be permitted to exercise but little practical
influence. 
LECTURE III.
  Heat is the subject for consideration this evening.   Fresh air is
the greatest of blessings, and to supply the necessary fresh air, ven-
tilation is, as we have shown, of  the first importance; yet we are
much more sensitive to heat and cold than to pure or foul air.
  Heat we  have to furnish, in  a great  measure, ourselves: pure
air is supplied us by the Creator.  Heat is the prime moving power
of the air: it is also the great controlling power of ventilation.   It
is the improper cold draughts that make ventilation so unpopular.
  Heat, therefore, is  the key that  unlocks the door for the  free
flow of pure air, *. e., for  good  ventilation.  Hence, if we desire
such  ventilation, we must  secure the key that unlocks the door
where the treasure is kept.   And now let us be sure to secure the
right key.
  There are three distinct methods of heating:
  1st.  Radiation—in which the pure,  independent  streams, called
rays of heat, come directly from the sun  or other hot bodies.
  2d. Conduction—or the means of conveying heat through solids,
when the particles of the heat are handed from atom to atom. And
  3d. Convection—which is  the condition wherein certain moving
bodies, such as air,  water, or other fluids and gases, gather  up an
armful of heat, as it were, and carry it away in their arms to other
parts.                             '
  Now, it is necessary that we fully and clearly comprehend these
three different ways of communicating heat.  It will require  a little
close attention,  but the understanding of it is not difficult, and then
the whole subject of heating  and ventilation, which may now appear
as a mystery, will soon begin to look quite plain and simple. 
 102            Golden, Silver, and dpper Heat.

   For the purpose of classifying the different kinds of heat more
 distinctly in our minds, let us term them according to their relative
 value, as follows:
   Radians* or  Golden heat;
   Conducted or Silver heat;  and
   Convected or Copper heat.
   This is about the  relative  value I put upon these different ways
 of communicating warmth, for our practical purposes.   Now let us
 consider these three  several ways of heating, a little more in detail,
* taking first radiant heat, or our " gold  heat," as that is much the
 most valuable.
   There is a tendency to a perfect equalization of that sensation we
 call heat, in all bodies.  If you should bring a block of ice into this
 room, and a red hot cannon ball, in a little while they would both
 have become  of the same temperature  as the room;  the ice may
 have changed form  and turned into water, but (no matter for that
 now,) the colder would have warmed  and the hotter would have
 cooled until all were of an equal temperature.
   The rays of heat—like the rays of light from the candle which
 I have here—are thrown in  every direction equally, just as much
 downwards as upwards, and just as much to the right as to the left.
   The special point  of interest to  us is the  effect  that the radiant
 heat has on the  air  surrounding us.  I want  you to comprehend
 clearly that it has no effect—it has no direct influence whatever in
 heating  the air.  The understanding of this is of great  practical
 value in our study of the subject of heating and ventilation.
   This room has air in it,  but it is not full, because, by properly
 pressing it down, we could  put in it the  air of another room of
 similar size, and by pressing it more we could add  another, and
 another, and so  on until we had got one hundred times as much in
 it as it at present holds; therefore, we must know  that it is not the
 one-hundredth part full.  But now again, if we were to commence
 at the top, supposing it to  be air-tight, of course,  and were to
 remove ninety-nine  hundredths of all the air  in the room, the
 remaining one-hundredth partvwould be evenly distributed over the
 whole space, so  that there would be just as much at the top as at
 the bottom.
   There must, therefore, be some other substance or property in tne
 room besides air, and which has the power of  separating the parti-
 cles of air and keeping them  equally apart  from each other.  And 
             Much Space between the Particles of Air.       103

herein we see exemplified anotner  oeuuului provision lor i^e uni-
versal distribution of the air;  so  that should man, or any livins;
animal, happen to be confined in a partial vacuum, yet all the air
that is there would be  equally distributed  throughout  that space.
  Now, suppose we compress our ordinary atmosphere one hundred
times; still the individual  particles do  not touch  each other, as
otherwise it  would  become a  heavy  solid: it  would then  only
weigh about ten pounds per  cubic foot, whereas the same  mea-
sure  of  gold weighs  more than  one  thousand pounds.  Hence,
each  individual particle of air must be separated  a great many
times its own diameter  from its nearest  neighbor—perhaps, one
hundred, or it  may be, one thousand times—for any determinate
number, in the present state of our  knowledge, would be purely
conjectural.
  Imagine a  regiment  of soldiers  drawn up in line of battle, but
instead of standing close together, they were to  be posted a thou-
sand times their own diameter, or  a quarter of a mile, away from
each other—do you not see  how many of the enemy's bullets might
pass through the line without hitting any one ?  These individual
particles of air, therefore, are so far apart that there is very little
probability of the rays of the sun, or the rays from any other hot
body, striking them; and I  believe it  is considered  that they are
ray-proof, even against  the few rays that might happen to hit them.
  Though I cannot illustrate this by showing you radiant heat, yet
the rays of light are  very  similar, and I will endeavor to make
the effect evident to you by a simple experiment with this candle.
I simply place  around the candle  an opaque cylinder that inter-
rupts the rays of light that  are going  directly towards you.   But
why do you not see the column of  rays that is passing directly up-
wards, and which you can  see by that small bright spot on the
ceiling ?   To make it more  distinct, I will move the light about a
little, and you observe the spot of light moves correspondingly.
  Now, the reason you cannot see that  column of light is because
the rays  move directly on through the intervening space, having
nothing to stop them until they get to the ceiling. I say "nothing,"
because the air is so near nothing that  it allows of no perceptible
effect; but now let us interpose something that will  stop those
rays—this piece of paper, for instance, will collect them, by which
the  disc  of light  becomes  quite  visible—and,  of course,  being
thereby obstructed, they cannot go on to the ceiling.  Or, by holding 
lr,4      Pure Air a Non-absorbent of Radiant Heat.

this smoking taper in the path of the rays, there is sufficient solid
material in the smoke to obstruct a large portion of those rays, and
the column thus illuminated is no doubt plainly visible to all.
  So you cannot see the rays of heat,  but they are passing through
the same space, and are very similar, in every way, to the rays of
light, the difference in the effect produced being considered due to
the difference of velocity  with which they move.
  That smoke will become heated as well as lighted:
  Experiments have proved that perfectly pure air, and the gases—
oxygen, hydrogen and nitrogen—do not  absorb an appreciable
amount of the sun's rays, and perhaps if they could be made entirely
pure, they might be found to be  absolutely ray-proof.  But you
know that the  moisture absorbs a great amount of the heat, because
a cloud (which is but visible moisture) passing over us of a hot sum-
mer's day is an excellent  shield from the burning rays of the sun;
and there is a large amount of moisture in the air at all times, even
when not seen in the shape of clouds.
  But you may say, we know that the air does get heated—how is it?
  We must again set our imagination to work;  we must endeavor
to see with our mind's eye those little particles of air, which we at
first supposed to be kept  constantly separated, and so far apart as
scarcely to get within sight  of each other, but which, when  we
come to examine,  we find are  really clustered together in little
groups or families. This we  know from the fact, that  where we
find one atom of oxygen (in the atmosphere), we are sure to find
with it  four atoms of nitrogen.  And again, we find that where
these air particles  become heated, Jhey are expanded,  (now a single
atom could not expand,) therefore we must conclude that they are
associated together, as just remarked, in little groups or families.
  The  sun's  rays pass  through  the forty-five  miles  of atmo-
sphere without heating it, but when they strike the solid substances
on the earth's surface the temperatures of the latter are very soon
raised.   We know this by putting  our hand on a board fence or
wall, when the sun is  shining on it, or on the curtains  or blinds
inside of the glass window, which become very much  heated by the
solar rays.
  Last winter I placed a thermometer in  a box, lined with black
cloth, and having put  a glass over it to keep the wind off, placed it
in a snow  bank:  the mercury soon  rose to 180°.   We can boil
water by the sun's rays even in winter. 
    Convected Heat the great Curse of the American People.   105

  Now, when these little groups or families, before mentioned, come
into actual contact with a hot substance, the heat is transmitted to
them by conduction—each group, so to speak, receiving its "armful"
or complement of heat.  Being expanded  thereby, they are made
lighter and forced upward, whilst other particles rush  in to take
their place; and  these latter, as they strike against  the hot body,
are in turn heated and caused to  rise, so that a continuous stream
or current is thus created.
  As this will be so constantly referred to in  our examinations of
the heating and ventilation of buildings, and as we ought to be able
to comprehend the principle so as to apply it for the regulation of
our own health and comfort every hour of the day, I hope you will
fully realize that there are two distinct  forces constantly acting in
opposite directions near every hot fire or other hot substance.   One
is, the rays of heat passing in every direction away from the fire;
and the other is the  flow of cold air towards that  fire, and directly
in opposition to the raj's of heat.
  But, that air is not heated at all until it  strikes  against the hot
body itself.  The most  philosophical way of roasting a turkey
therefore, is to hang it up in front of a hot fire, and use  the golden
rays of heat to cook it,- while the cold, pure, concentrated' air is
flowing by it into the fire.
   Conducted heat has less influence upon us, perhaps, than either of
the other systems.   As we  are affected in this way only by those
things that come in immediate contact with us, of course the better
or worse conducting power  of our clothing has much  to do with
our comfort.
  But  convected heat is the great curse of the American people.
It is that dry, lifeless, withering,  debilitating, poisoned stuff with
which  most of our best  houses and public buildings, and,  most
unfortunately,  many of our  school houses,  too,  are  filled  and
warmed;  and which is filling our systems, and warming and dry-
ing the life and substance out of  about two-thirds of the people of
this country.
  I have, for the last three or  four years, been giving very  close
attention  to the comparative  merits of radiant  and  convected
heat.
  I formerly supposed that a room warmed by air from a hot
water apparatus was as perfect as any artificial arrangement could be,
but more careful recent investigations have shown me my great mis- 
106            Keep) the Feet and Back  Warm.

take.  Let me first say, however, that hot water is probably the
most perfect means of warming what air we must have warmed.
  But what I mean to express, particularly, is, that we should be
surrounded with and breathe cold air, and  receive the heat required
for the body by direct radiation.
  This is just the reverse of what we  generally experience in our
furnace-heated houses.  There we have a little hot,  dry air—the
air itself being hotter  than the temperature of the room, and  the
walls, especially the windows, colder.   No more  unscientific, un-
healthy and uncomfortable  condition  could possibly be imagined
than this.
  Our Creator has provided for  a constant difference between the
temperature of our bodies  and  the air with which we are sur-
rounded, for a wise purpose; and we  find the greater that differ-
ence, the more active and vigorous is the  action of all our animal
functions.   As  I stated the other evening, there is nearly double
the quantity of carbonic  acid given off in  a temperature of from
10° to 20° that there is in a temperature of 90° or 100°.
  From this we would argue that when we are breathing air at this
very low temperature, we are twice as active, and can do twice
as much work, as when we are breathing air of nearly the tempera-
ture of our own bodies..  We know how very languid and good-
for-nothing we feel on a hot summer's  day; and, on the contrary,
how fresh and vigorous we feel in the  open air of a cold, bracing
winter's day, and especially when the glorious golden rays of sun-
shine come pouring down upon us  with all their richness and
splendor.
  Now, I think we shall  be able to apply these principles to the
heating and ventilation of rooms.
  We must study to comprehend the principles,  because the cir-
cumstances  surrounding  us  are  varying  so constantly  that such
arrangements as would suit us best at  one time, would not be good
at another.
  A primary condition to be observed  in all heating and ventilating
arrangements, as before alluded to, is to keep the feet warmer than
the head, and the back warmer than the face.
  These are great  natural provisions, as in walking,  or  when
in motion we face  the current.   We inhale from the  air in front
of us, and the fouled air is carried behind us.  For  better pro-
tection, probably the greater portion of the nerves are concentrated 
The Sun the best Heater.
107
near the spine; consequently, if the back is chilled, the whole system
is put out of order; and more care is required to keep the feet warm,
because, being farthest from the heart, the blood is more liable to
become chilled, but if the extremes  are kept warm, of course the
intermediate parts must necessarily be so.
  The sun's rays falling upon the earth's  surface, and  heating our
feet hotter than the air around us, is a beautiful  illustration of this
principle.
  Nearly all animals except man, secure  this condition by build-
ing their houses, or burrowing below the ground, so that the warmth
of their bodies causes the foul air to flow out, while the cool, fresh
air to supply its place, must come in from above, and consequently
fall upon their  heads first.
  It must be admitted that most of our arrangements for ventila-
tion and warming do not fully meet  these  requirements ;  indeed, a
careful examination will reveal the fact that many of them are as
absurd and  unscientific as they can well be made.
   I have here  a diagram  (see lithograph  Plate, Fig. 10), which has
been prepared to represent the  condition of different parts of the
room, when heating exclusively by open fires.
   I have been  unable to invent or think of  any simple method of
showing the actual passing or currents of  radiant heat.
   It is one  of the most difficult points to comprehend in connection
with the subject of heating and ventilation.  It is also one of the
most important.
   In this diagram, we have resorted to colors to express our ideas.
By the blue is designated the strong current  of  cold air that is
usually found flowing along the, floor from the windows and doors
towards  the open fire;  and of course the feet and back of those
sitting with their  faces to the  fire, are most affected by this  cold
air. . It may at times be  but little above the freezing point; but
directly in opposition to this current there is a strong  radiation
from the bright fire, directly into the face  and front of those sitting
before it, as represented by the figure of the man in the cut.
    We must remember the  direct radiation from  an open fire or
other hot body is not disturbed by the current of air.
   Now to get his back warmer than his face, and  his feet warmer
than his head, it will be necessary to change his position.  (Fig.ll.)
  I admit, this is rather an awkward position.  But you know the
conventional way for an Englishman to represent a Yankee, is to have 
108            An Open Fire good Ventilation.
him tiited back in a chair, with his feet on the mantel, or in some
position higher than his head.
  So you see there is a little more  practical  common sense about
this position of the universal Yankee, than would appear at first
thought.
                           .   .                  .   *
  Now, I do not suppose this will become  a  fashionable way ol
sitting, as represented by Fig. 11,even if the physiologists were to
recommend it. But if we want to be really comfortable and healthy,
we  shall have to change either our manner of sitting, or our man-
ner of heating and ventilation.
  Let us consider this open fire question  a  little carefully, because
there are some very good points about it.  The heat derived from
actual combustion, that is from an  open fire, is the purest artificial
heat we can possibly have.   The temperature of the burning coals
or wood is  near  3,000°, and the  flow of  radiant heat therefrom
more nearly imitates the sun than from surfaces of a lower tempe-
rature.
  This is the strongest point in its favor.   It is also impossible to
prevent its being* a good ventilator.  And this is  no small account
to its credit, as it is almost the only ventilation that the people, in
their ignorance, do not stop up.
  But  it also has its disadvantages, which have prevented, and
always must prevent its coming  into universal use for heatino-
exclusively.
  One of these is represented by the diagram in the very uneven
manner of distributing the heat, and as it  heats the head hotter than
the feet, and the face hotter than the back,  we shall have to ignore
it altogether, or what I think will do better, get some additional
assistance partially to warm the air before it enters.
  Let us now consider the great abuse  of heating by direct radiation
without the proper fresh air supply. We have prepared some tanks
for using in the lantern, and by using liquids of different colors
and densities, I think we shall be able to express to you some
of the principal movements of air of different temperatures.
  If you will notice  carefully, you will  soon see that the liquids
used to-night are  governed by the same  laws, and move in almost
precisely the same manner, as the air and gases of different den-
sities that we used' the other evening.
  Professor Morton has very kindly offered to assist me this  even-
ing, and has now placed in the 'intern a small tank, and by the aid 
FIG-.  1
 
 
Heating by the Stove.
109
of the new Zentmayer prism, shall be able to show you the image
on the screen, just in its natural position.
  This we could not have  done last year, without the aid of this
prism, and as we would have had to work everything bottom up-
wards, I did not then  use the lantern for this purpose.
  At the left hand corner of our room, (Fig.l2),you see the shadow
of a small coil, which is fine platina wire.   Professor Morton will
connect the two ends of that coil with a small battery, and thus put
a current of electricity through it, by which it will be heated,  and
you will very soon see the  liquid around that coil (represented by
stove in the figure) beginning to ascend.   And now you see, as the
air around the stove commences to rise, the air from below flows in
to take  its place, thus giving a revolving motion to all the liquid
in the room.
  You also notice the  figure of a  man sitting very quietly, with
his back to the window, as  though he was in a profound meditation.
  We will have to disturb his  quiet a little, I think.
          [Here the figure was made to imitate breathing?)
  You see, the breath being loaded with carbonic acid and moist-
ure, falls  directly to the floor,  and mingling with the revolving
mass, will soon be carried  quite around the room, and back again
to be re-breathed.
  This is  a combination of warming by direct radiation, and warm-
ing the air also by its coming in contact with the stove.
  Now please take especial  notice of the conditions  here repre-
sented.  This applies  to a  large number of our ordinary buildings
heated by steam, when the  coils are placed directly in the room.
  It also  very nearly applies to rooms heated by air-tight stoves,
as there is so little air consumed in them to support combustion, it
is hardly worth noticing as ventilation.
  The air is  already becoming very foul,  as it  inevitably does, in
rooms treated in this manner, when no attention is given to having
a regular  supply of air.
  It allows the room and all its inmates to be sealed up perfectly
air-tight.  It not only allows it to be done, but we generally fine!
that advantage is taken of  this opportunity to close all cracks,  and
it is most zealously accomplished.
  There  is one other point of much practical importance repre
sented in this:  that is, in sitting with the back towards a cold win
dow; the additional warmth or animal heat of the body will be radi- 
 110            Improved Method of Heating.

ated to and absorbed by this cold window. And thus the very being,
life', and vitality will be abstracted, and spinal disease, rheumatism,
and all sorts of disorders, are the results frequently of continued
-itting in this position.  Therefore, never sit with your back to a
window.   And we must remember the thermometor is a very de-
ceptive guide to go by for ascertaining the temperature of  the air
in a room, as it may be surrounded by air at 100°, yet only indi-
cate 70°, the difference being the loss of heat by radiation to a cold
window or wall.  And, on the contrary, it may indicate a tempera-
ture of 75° while being in an atmosphere of 50°, the difference
being the effect produced by the radiation from  a fire," hot stove or
similar substance.  It will be observed, that the cooling of the air
by its coming in contact with the window, by no means purifies it.
   Now, this is the great abuse of direct radiation ; the way  a large
proportion of our buildings and rooms are arranged.   I think we
can make an improvement on this. (Fig. 13).
   In the first place, the  heating surface  is represented  in this case
as a coil of steam pipe, but it may be an  open fire or stove  or any
other heating arrangement, and is  placed on the cold  side of the
room and directly under the window, which, being but thin glass,
is generally the coldest part of the room.
   Now, by raising the window a  little, there will be a current  of
fresh air blowing directly against this heating surface; the entering
air will thus be partially warmed.  It need not be warmed to the
temperature of the room, however, because there will be a large
proportion of the heat derived from the direct radiation of the ex-
posed heater.
   This gives the very great advantage of having cool, invigorating
air for breathing, while the body is warmed by the direct rays from
the fire or other heating surface.  It  also prevents those cold, un-
pleasant draughts so commonly complained of near windows.
   The temperature of the fresh air, too, being so near the required
temperature of the room, has no special  tendency to rise immedi-
diately to the ceiling and escape through any opening that may  be
made there.  On the contrary, being rather cooler, it is first in-
clined  to fall to the floor, and only rises when it is additionally
warmed  by the persons, gas-lights,  heated floor, or some extra
warming surface.   The ventilatois  at the  top  of the room can
always be left  open without  inconvenience, with  this arrange-
ment ;  this, too, is a very great advantage, as they should  always 
          Floors and Outside Walls should be Warmed.      Ill

be open  in  the evening under all circumstances, to carry off the
products of combustion from the lights;  and it is so difficult to
have them opened in the evening and closed in the day time, with
our present careless and indifferent notions about ventilation.
  Therefore, an arrangement not  requiring this daily  attention, is
valuable.
  This combination of direct radiation and circulating fresh air—
partially warmed—with the excess of heat directly under the win-
dows where  the excess  of cold occurs, is probably as nearly perfect
as any arrangement yet devised.   Of course, it would  add greatly
to the completeness thereof to have the floors and walls warmed to
about the temperature of the body, to  prevent the abstraction of
the animal heat therefrom.
  The figure represents an additional foul air channel under the floor.
The air is represented by the  arrows being drawn from the floor of
the room around the base-board, and in schools or meeting-rooms
when large numbers are assembled it should be drawn from numer-
ous points over the floor. This, frequently, for large, crowded rooms,
is an important arrangement.
  Of course, these general plans will require many modifications in
practice,  and much  ingenuity may be expended in devising the
most perfect manner of accomplishing these important  results; but
I think these suggestions for reversing the effects of our  ordinary
method of warming  are very necessary to  command success,  and
we had better make  up our minds to act promptly, decisively and
energetically in endeavoring to bring about the much needed gene-
ral reformation.
\ 
LECTURE  IV.
   Sixoe  preparing  these  lectures on  ventilation, I  have  taken
 occasion  to  remark  to  many persons, on meeting them,  "lam
 delivering a course of Lectures on Ventilation;  are you interested
 in that subject?"
   I suppose nine times  out  of ten I receive for answer-1—"No, I
 never took any particular interest in it."
   Do you breathe ? I ask.  Looking rather astonished at such a
 question,  they generally  say—"Yes, of  course," and I ask if  they
 think it makes any difference whether the air they breathe is pure
 or foul.
   " Well, they suppose it does, but they have never thought much
 about it."
   Never have thought much about it! that is the trouble.   Now,
 my opinion  is, that  it is about time we had thought something
 about it.
   Between six and seven thousand children died in  this city, last
 year,  under six years of age—more than half of the whole number
 of deaths  in this city.
   Did you ever hear of a shepherd losing half  of his lambs by
 sickness before they were half grown—or a farmer losing half  of
 his calves, or half of his colts?   I don't  know precisely,  but I
 suppose 3 per cent, would be a full average of such loss, instead  of
 50 per cent.
   Now, what is the cause of  this great difference ?  The shepherd
 keeps his lambs in the open air, in a great measure, and so does the
 farmer  his calves and colts.  But  you shut your  children in your
 close, unventilated houses; you wilfully and persistently deprive
 them  of  that pure air their Creator  has made such  wonderful
 provisions for supplying them with, and has made so  essential for
 their health, and their growth, and their very existence.
   You shut them up and  smother them in your foul bed-chambers
surrounding them with this poison of human breath—that is too
foul to support  the combustion of a candle.   You poison  them  to
death 1 
Foul Air more Destructive than War.          113
   I have hung on the sides of the room—one on the right and the
other on the left—the two lists of tables of the analysis of the air
I copied from a report to Congress on the ventilation of the capitol,
made  by Professor Henry, Thomas U. Walter, and  Dr. Wetherall.
(The same tables used last year—see page 17.)
   The one on your right hand shows the amount of carbonic acid
in  the open air; and the  one  on the left, the  amount found in
buildings.
   By an examination of these you wall readily see that all external
air, such as the  sheep,  and calves, and colts  have to breathe,  is
uniformly very  pure, while that  in  houses, such as  we  and our
children have to  breathe, is very different.
   You see here  in our scientific  lecture-rooms, school-houses, bed-
rooms, we  have 50,  60,  and even  72 parts of carbonic acid in
10,000.
   It is that excess of carbonic acid—over 5 parts in  10,000—that
represents the foul, poisonous condition of the air  of our houses,
which is killing half the people of this country.
   I consider these tables valuable, because they are nearly all the
analyses  of air that have ever been made.  Comparatively speaking,
we do not know anything about that subject as we ought to know.
   Let  me ask you if it  is not passing strange that a great and
intelligent nation, like the United States, should so  utterly neglect
this important subject?  A nation that can  raise such vast armies,
and can raise millions,  hundreds and  thousands  of millions  of
dollars for destroying each other in  time of war, yet  scarcely one
dollar for analyzing the air and endeavoring to control it and prevent
the destruction of human life by that fearful poison—foul air—that
killed more persons in the United States last year (a  year of pro-
found peace) than were killed on the Union side by  sickness, and
by the enemy during the entire late wTar.
   If there is a case of poisoning by arsenic or strychnine the whole
city is  thrown into a state of feverish excitement, and if  not sus-
pected until after the body is buried, it is exhumed and the most
skilful chemists work  faithfully over it to ascertain, if possible,
some trace of the poison; and yet, some 3,000 children wrere poisoned
to death  in this city by foul air last year, and can you produce one
solitary record of the  analysis of the air of the room in which they
were thus killed?
   Is there one of your medical colleges, the boast and pride of this 
114
Ventilation of the Capitol.
city, that teaches its students, by careful analysis of the air, readily
to detect and how to remedy those  impurities which physicians
must constantly meet with in the sick-room ?
  Shall we not hope that the day is not far distant  when the people
will be aroused from their dreadful  apathy and indifference upon
this subject ?
  We now propose examining the ventilation and heating, as it is
applied in various public and private buildings with which  you are
familiar.
  It is not a pleasant task to examine and find fault with the new
and splendid buildings that have just been completed, at such great
cost, and which are looked upon by their owners and most casual
observers as models of beauty and perfection.  But, are not  these
buildings  the true index of  the general  public  information  upon
these subjects?  And is it not, therefore, best for all of us  that we
should give them  the most critical examination, and  if they  are
merely showy tombs as it were, and entirely devoid of the proper
supply of  that life-giving element, pure air, to acknowledge  the
truth promptly and  then set ourselves  to work  energetically to
endeavor to  learn the best way of improving these, and avoiding
such mistakes in all new ones %

                         THE CAPITOL.

  Professor Morton will first throw  on the screen a  fine view of
the Capitol at Washington—this is at all times an interesting build-
ing to an American.
  And perhaps there is no building in the world upon which there
is such a decided diversity of opinion among scientific men as to
the perfection of its ventilation as there is respecting this building.
I have devoted much time for many years past to studying its pe-
culiarities,  and I think if the mere question of a constant supply of
air to  the main rooms was the only one, it can readily be proven
to be well ventilated,  and yet it would be very difficult to  get  any
considerable number of the  owners who are obliged to occupy the
building for a large portion of the  year to consent to any such
statement.
  The universal  dissatisfaction is probably owing as  much  to the
quality of  the air supplied, and the manner of  heating it, as  to the
quantity. 
Badly Warmed.                    115
  I consider this a good example of the ill effects of that detestable
system that we as a nation have fallen into, of attempting to warm
our buildings by over-heating, and thus ruining all the air used for
breathing.
  The total absence of any direct radiation is  a marked feature,
for there is not only the  entire absence of  any artificial radiation
from  exposed steam-pipes, etc., but there is the  additional absence
of radiation from the great natural source of all heat, the  sun.
  The direct rays of the sun I believe to be not only the most mag-
nificent warming power, but  also the  greatest disinfecting and
purifying power we have, and they are of the utmost value for the
vigorous development and exercise of all our physical and mental
faculties.
  It appears to have been originally designed to exclude the main
halls as much as possible from all external influences, and to have all
the currents, the  heating and the lighting, under perfect  artificial
control.
  But if the whole nation could  be taught the valuable lesson, of
the great folly of attempting to  produce artificial light, artificial
heat, and artificially mixed air, that shall be equal to that which our
Creator has  provided  for us, that knowledge  would be cheaply
bought  at the great price paid for these buildings.
  This diagram wre have here is a  copy of a plan made to accompany
a report to  Congress which was published January 20,1868.
  I tried a large number of  experiments during the winter of '67
and '68 to ascertain the direction of the prevailing currents through
the Hall of Representatives, and the relative temperatures in all
parts  of the  building.   I was rather surprised to find them so  dis-
tinct and well defined, and also that they were so free from disturb-
ance  by the changes  in  the direction and  force of  the external
currents.
  The heat all entering the hall, or passing under it on the west side,
gave an additional temperature of 4° or 5°, which was sufficient
to cause an  ascending current at that end, wmich produced a cor-
responding descending current at the other end.  A very striking
feature was the effect of the exposed copper roof  in cooling  the
foul  air and causing  it to  fall  back again on to the floor of  the
house.
  It  will be seen by reference to these figures  (see diagram) that
when the thermometer indicated 61°  near the floor, the thermome- 
116         Ventilating into an Open loft very Bad.

ter over the glass ceiling indicated 56°, while those around the sides
were only 40° and 38°.  I  found a strong descending  current of
this cooled foul air descending  on  three  sides,  sweeping over the
galleries, and tumbling down on to the floor.
  This was bad enough through the day, when the air was only
polluted by human beings, water-closets, steam-engines, restaurants,
etc.; but at night, when the products of many  hundred gas-lights
were added to it, it became  almost insufferable.  I noticed that in
four minutes after the gas was turned  on for lighting in the loft,
we  perceived it on the  floor, and in fifteen minutes it became very
oppressive.
  I wash to call your attention particularly to this system of ven-
tilating directly into a loft;  I find it very often in churches, and in
many other buildings where the openings are made directly into
this space under the roof, and frequently in schools a whole system
of flues will empty into such a place.  Sometimes there will be a
small blind window in  the gables, and sometimes a small ventilator
on the roof, but not connected with the ventilating flues.
  This is all wrong,—a very deceptive, pernicious system.   If there
is any circulation, there is almost sure to be a  descending current
of cold foul  air where you. do not want it, or very commonly there
will be but little or no  current at all—and  such ventilators will be
mere deceptions, much like  that handsome frescoed ventilator on
the  solid wall of the Washington church.
  Much care should be taken to prevent the escaping foul  air from
being cooled down below the temperature of  the  room  so  as to
cause it  to  return; the  exit pipes should be continued of one
uniform  size until the foul air is delivered entirely out of the
building.
  To return to the House of Representatives:—Now, when you add
to this revolving and continued resoiling  treatment of the  air after
it gets into the hall, the source from whence it comes, I think we
have excuse  enough for the complaints  of those country members
who have been accustomed to tolerably pure air.
  Some of  the  members, who have been  lawyers, and therefore
obliged to spend much of  their time in our court-rooms  and city
offices, and newspaper editors, seem to  be very much at  home in
such an atmosphere—they may enjoy it.
  The fresh! air is taken in through the basement into the cellar,
and there forced  up by fans through an immense stack of dirty, 
  Zewis W.leedr.
£nfr efVcnt"! IrHtat.
PLANS  SEO>MXG IMPERFECT VE XTILATION AND  HEATING
      HALT. OF JREFRESEXTATIVFS WASHINGTON TJ.C. 
 
 Absence of Carbonic Acid not Proof of Perfect Ventilation. 119

 rusty iron pipes,  coated by many  years' accumulation  of rust,
 particles  of  decaying animal  and  vegetable  matter, roasted up
 afresh  every  day; from  thence  it is driven through  a labyrinth
 of un cleaned horizontal  air-ducts, filled with  the moulding and
 decaying dirt that has  collected for years,  and finally driven
 through the  uncleaned spittoons (originally intended for registers)
 arranged all over the floor of the house, issuing into the room at a
 temperature  of from 100° to 120°—a warm,  debilitating, filthy,
 disgusting mass for the members to breathe.
   And yet some  of the committees, in  making very  elaborate
 examinations  and  reports to Congress, fail to discover any very
 excessive amount  of carbonic acid,  and by counting the number
 of revolutions of  the great fan, and calculating how much fresh !
 air ought to be thrown in at each turn thereof, suppose there must
 necessarily be an  abundance  of air, such as  it  is, sent  into the
 building somewhere  ; consequently they declare it to  be  the best
 ventilated building in the world.
   But these reports have not generally given very accurate infor-
 mation as to the effect upon the  members of breathing air nearly
 the temperature of the body while being surrounded by cold  walls
 and a cold roof,  nor how  much of the cooked  grease from the
 engine, or  the smells from the water-closets, or gas from the
 illuminating loft, etc., etc., is mixed up with the air.
   As an offset to  the very scientific  reports proving this building
 to be the best ventilated  one in the  world,  I  might relate  an
 incident that  occurred while the  building was  used for a hospital
 for wounded soldiers.
   On entering the  House  of  Representatives  one morning,  I
 noticed a very disagreeable odor, and traced  it to a young  man
 with an amputated limb  just by the  speaker's desk; he seemed in
 much distress, and  the  anxious look  of his father and mother (I
 think from Western Pennsylvania) led me  to inquire a little  after
 the condition  of their son.  I soon learned that their special grief
 was the disappointment in not being allowed  to  move their son
 out of that room on to the porch, where he could get a  little fresh
 air !   They had been promised this  privilege  the day  before, but
 had been denied it again that morning.
  They seemed very anxious to have me intercede for them, and
the father followed me out  and said, if any money could  buy the
privilege of having his son moved, he w-ould willingly pay  for it. 
120  Suggested Improvements in  Ventilating and  Warming.

  Can I add any words of stronger condemnation than this touch-
ing appeal of a wounded man for  the privilege of being removed
from this magnificent room to the outer porch that he might get a
little fresh air and sunlight ?
  Here we have another diagram prepared at the request of some
gentlemen of this city,*  showing some  suggested modifications
of the ventilation and warming of  the Hall of Representatives.   It
is proposed to draw off the foul air both at the top and bottom.
  That taken from the bottom is to be drawn through the present
inlet registers, and that from the top to escape around the sides of
the glass as at present, and through the illuminating loft to the
external air.
  Now, wdth a little ignorance or carelessness it would  be very
likely to be  so arranged that discharging the air in two opposite
directions might  make  confusion, and that it would, at times, all
draw up, and the  foul air, instead of escaping at the floor, would
flow in there ; and at other times it would escape  at the floor  and
come in at the ceiling; but it is very easy to avoid such action  and
writh entire certainty.
   This is the proper manner to arrange all large buildings intended
to be occupied by a considerable number of persons ; there should
be  escapes for foul air thoroughly distributed over the floor,  also
liberal escapes  from the ceiling, and  these  should be kept con-
stantly open when the room is occupied, and there is no practical
difficulty whatever in doing this.
   It was originally intended to overflow the hall with the fresh air
driven in by the fans; but,  practically, this is not  the  general
condition.   Several experiments, tried at various times, indicated a
strong current  setting into the Hall of Representatives from  the
corridors through every door, both above and below, so that practi-
cally the main room is  supplied  by air from the  surrounding
passages ; we consequently recognize this fact and act accordingly.
Arrangements should therefore be made  to keep the  air in these
passages as nearly pure as possible.
   It is proposed to warm the floors of the hall slightly in excess of
the temperature of the room, say to about 80° or 85°, which would
still be below the temperature of the body; and  also to have all
the exterior walls warmed so that there would be a gentle radiation
from all the  solid bodies  in the room.  When we  are  not losing
* Rand, Perkins & Co., of Philadelphia. 
 lewis H Lee
€n9r tfVeif * >i
PLANS  FOR IMPROVING THE VENTILATION AND  HEATING
     HAT.T. OF REPRESENTATIVES WASHINGTON I> C. 
 
                Cool Air Introduced from Above.            123

heat by conduction, from contact with a cold floor,  and are  receiv-
ing radiant heat from all the surrounding walls, instead of parting
with the warmth of  our bodies to these walls, we can afford to be
surrounded with  and have  the luxury of  fresh, cool, invigorating
air for breathing.
   As the corridors would be largely warmed by radiation the air
in them wrould be cooler than the indicated temperature;  it would,
consequently, flow into the hall underneath the air longer contained
there.
   It is not intended, however, to depend exclusively on the  supply
of air from the corridors in case the doors should all be intentionally
or accidentally closed; there wrould be an abundant supply of air from
portions of the perforated ceiling.  In winter arrangements "would
be made to warm this to the required  temperature, but as so con-
siderable a portion of the warmth of  the hall would be furnished
by direct radiation, it  would only be necessary to have this  air
heated to 50°  or 60° ; consequently, being slightly heavier, it would
easily fall in gentle, well-diffused currents, to take the place of the
foul air drawn out both above and below.
   Many persons  are afraid  of a  draught of cold air upon their
heads, but if the surrounding conditions are right this is just the
position t.< > have it strike the body.  For instance : I have stood on
the hot plates  in front of the boilers  in the hold of a steamship,
with my back towards the hot boilers,  and had a perfect torrent of
very cold air falling on the head, which felt  delightful.
   The firemen are  constantly subjected to this without injury, but
if they go on  deck and stand in a  draught, or cool off quickly,
away from the radiant heat, they frequently take severe colds.
   One difficulty about having a cold  draught upon your head: it
is very apt to be colder on the feet, but that part is  frequently not
noticed.
   It is also  proposed to put in  a row of dormer  windows, that
would let in more sunlight, and perhaps some of the direct rays of
the sun, and  in  summer would  be very useful  in catching  the
breeze as it passed  and throwing it directly into the hall  as you
see here  (refer to diagram).   It is  proposed to entirely disconnect
the illuminating loft, so as to avoid the possibility of a returning
current of foul air as now  occurs;  also  to make an additional
plastered ceiling and  a confined air-space  to prevent  the rapid
cooling effect of the exposed copper roof.
              8 
 124             Certificates of Leading Architects,

   It is proposed to dispense with  the fans  entirely, which I  con-
 sider  about  the  greatest  nuisances in  the  building,  and  rely
 exclusively on heated shafts.
   The  same  amount of heat applied to a  well-constructed  shaft
 will probably move a  much larger amount of air, at a  great  deal
 less cost, and requiring no expensive engineering attendance.
   I believe if this plan  was carried out it  would make  a very
 satisfactory building; perhaps the Hall of  Representatives would
 not be  quite  equal  to a single room, with  the walls  and floors
 warmed, and large windows on all four sides for the free admission
 of  air and sunlight,  but it would be so  much  better  than many of
 our public halls, that by comparison it would be considered very
 good.
   Since the completion of these drawings I have shown them to many
 of our leading architects, and the  accompanying certificates, which
 have been endorsed on the  back of those plans,  show how univer-
 sally these principles have been  approved by the architectural pro-
 fession, and  they are  now making arrangements  to have them
 adopted in most of their new buildings.

                                             New York, January 28th, 1870.
  The plan of combining fresh air supply with direct radiation is, I feel con-
 vinced, the arrangement that must ultimately be followed in all large public
 buildings, and the place of bringing the external air  into each room through
heaters under the windows is, I believe, the most simple and effective adaptation
 of the general idea.
                                                   Calvert Vattx.
                                             New York, January 28th, 1870.
  Engineers of ventilation and heating, in my judgment, lay too much stress
upon the necessity of supplying fresh air to an apartment by mechanical  appli-
ances.  The theory of Professor Leeds has for a basis the taking advantage of
the  natural currents of air; the radiators are placed immediately under the
windows where fresh  air constantly  passes over them, and  is warmed to any
desired temperature, and the air thus admitted is most agreeable in quality, and
free from debilitating effects. The more diffused the inlets  for fresh air, the
more uniform and agreeable the temperature.  The inlets  for foul  air should
also be diffused and placed both at  the top and bottom of the room.   The
system of Professor Leeds is heartily indorsed by me, and  seems to have every
advantage over any system having "fans" or similar appliances as a basis.

                                  Edward H. Kendall, Architect,
                                            92 Broadway, New York. 
Showing Approval of these Suggestions.          125
  I have examined the plans of Mr. Leeds for the ventilation of the House of
Representatives.  It is founded upon the system approved by the Commission
of the Exposition of Paris as the best, namely, the introduction of fresh air at
the top of the chamber and exhausting from the bottom, and I have no doubt
that if the air introduced from the top is properly warmed the method proposed
by Mr. Leeds will be perfectly successful.
                                              James Renwick, Architect.
  Recent investigation has strongly impressed me in favor of warming the
floors in excess of the required temperature of the room, say to nearly the tem-
perature of the body, and if this can be done satisfactorily, so that the fresh air
required for producing the necessary ventilation may enter cooler than the air
longer in the room; thus it may no doubt be found entirely satisfactory to ven-
tilate at all times from the top of the room.
                                          G. P. Reandall, Architect,
                                                            Chicago, 111.

                                               Pittsburgh, pa., Feb. 10th, 1870.
  Having studied the subject of heating and ventilating public buildings for
the last thirty years, and having had the advantage of the personal instruction
of Dr. D. B. Reed, of  Edinburgh, Scotland, in 1840, both in Edinburgh, and
in London at the Houses of Parliament, I most unhesitatingly endorse the views'
and plans of Lewis W. Leeds,  and have introduced the same into the new City
Hall of this place.  The plan of warming the  floors as proposed by Mr. Leeds
meets also with my warmest commendation.
                                                  J. W. Beer, Architect.
                                                          29th January, 1870.
  The exit of foul air should be both downward and upward;  downward for
the quicker escape of the products of respiration, and upward for the escape of
products of combustion, both kinds of foulness being carried  off directly from
the points where  they  are  produced without vitiating the  air of the whole
chamber.  This provided for, and direct radiation being given for warmth, the
entry of fresh air is rendered easy.  Tins fresh ah may be warmed at entering,
or not, at pleasure.
  Mr. Leeds' plan seems to us to meet all these conditions and to be based on
the soundest principles of ventilation.
                                        Russell Sttjrgis, Jr., &  Co.,
                                                          87 Broadway.
                                         Richard M. Hunt.
                                                          January 31st, 1870.
  I agree entirely with the above statement.
                                         Geo. B. Post, 6 Hanover Street.
  Being requested by Prof. Leeds to express my views on the subject of heating
and ventilation, I have no hesitation in saying that I believe the theory that all 
126
Continuation  of  Certificates.
foul air must  be drawn  from the floor alone,  without any provision for its
escape from the  ceiling to be radically wrong.  This  course may perhaps be
rendered necessary where attempts are made to warm the building by currents
of warmed air only.  But, in my view, it is a great mistake to attempt to reverse
the order of nature and to make the currents  of warm air which surround the
human body turn downwards.  The manner of  applying the heat and ventila-
tion shown in these drawings  is undoubtedly correct in theory, and if faithfully
executed would,  I doubt not, fully accomplish the intended purpose.

                                                 Arthur Gilman,
                                          98 Trinity Building, New York.
                                                         February 17th, 1870.
  The views here  expressed by D. H. Kendall, Esqr. (Architect), of New York
City, so clearly and fully set forth' what I have  adopted as my practice after
many years of experience in the subjects of warming and ventilating of build-
ings, that I desire only to say, that I most fully concur with that gentleman, in
the opinion he has  given.
                                          Samuel Sloan, Architect,
                                    154 South Fourth Street, Philadelphia.
  The above is endorsed by
                                    Carl Pfeipper, Architect, New York.
                                                   BOSTON, February 25th, 1870.
  The idea  of warming and ventilation, illustrated herein by Mr. Leeds, seems
to me to be the correct one, viz.—a well-distributed supply of warm  fresh air
combined  with direct radiation and a distributed exhaust of the foul ah, not
merely at the bottom or  top, but  at both.   Without going into  detail, the
system seems to me to have been  adapted to  the hall in question  with great
completeness.
                                           Samuel F. Thayer, Architect.
  Mr. Leeds' system of ventilation  has long been familiar to us, and we have
made use of it in our practice with  satisfactory results.  The application to the
Capitol at Washington, as exhibited in these drawings, is ingenious  and eco-
nomical, and satisfies all the  conditions of natural  ventilation,  both in winter
and summer, avoiding violent currents of heated ah*, and  distributing  an equal
temperature.   This plan  is capable of  all those modifications which may be
needed in adapting it to new  conditions.
                                                 Ware & Van Brunt,
                                             2 Pemberton Square, Boston.
                                                          February 25th, 1870.
  We have been giving great attention of late years to the  comparative value of
warming by hot-air currents and by the combination  of direct radiation; and
the result of our experience convinces us that it is very essential to perfect com-
fort in cold weather to have a well-diffused radiating surface in every room, and 
Treasury Building.
127
that the general supply of air for ventilation should be cooler than the indicated
temperature of the room.  If properly constructed,  we believe good exhaust
shafts, heated at the bottom, are entirely superior to produce the necessary ven-
tilation in all ordinary  rooms, and  are better than forced ventilation by fans.
We believe the plans as proposed herein by Mr. Leeds for the Capitol will give
very satisfactory results.
                                           Cummings & Sears,
                                        10 Studio Building, Boston.
              THE TREASURY BUILDING, WASHINGTON.
  We have here several drawings to illustrate the  condition of the
ventilation and warming of the U. S. Treasury buildings.
  This  is  one of the most substantial and expensive executive
buildings in the world, having cost some $5,000,000.
  No expense has been spared in  any part  to  make it the  most
perfect, comfortable, and convenient building that the ingenuity of
man could devise.
  I wish you to make a distinction here  between  the errors of
original design and construction, and the troubles resulting from its
shameful abuse, because the former showT the deficiencies of correct
knowledge in this respect among the best informed architects and
builders; but  the most shocking condition of the old  building and
ill health of  the occupants, as I  found them,  result very largely
from the shameful  abuse of it after its completion, and  show us
the want of general information in the public, which will prevent
the very best  arrangement that could possibly be made becoming
an intolerable nuisance, as was the result here.
  It  must be  remembered that this whole  block has been many
years in building and reaching its present size.  The plans repre-
sent it, as now finished, as a single  completed building, but we must
examine it in parts, according  to the ages in which it was built.
  The old front on Fifteenth street has been built probably fifty
or seventy-five years—quite long enough, at any rate, to show in its
original construction those  ample old-fashioned fire-places  where
hickory wood, and plenty of it, was burned in each room.
  And  -when  these  were in full  blast an examination of the
absentee list would show a much smaller proportion of excuses for
sickness from foul  air diseases than  at present, with  these fire-
places carefully boarded  up or walled on top,  and all  the rooms
heated from one large central  boiler in the cellar. 
12S           My own Experience with Hot Air.
  Most of this part of the building has been remodelled, so as to be
heated by radiation from hot-water oils in each room, great care hav-
ing been taken to shut up all crevices to prevent any cold draughts.
  The south wing and west wing have been completed much more
recently—mostly  within ten  years.   This  is  the  portion of  the
building which I wish you to examine more carefully.
  That  cleanly and  refined system of  murdering human beings
which has spread  like a devouring pestilence over our whole land,
came into general use about the time this building was designed.
  I mean that miserable system of warming our rooms by currents
of over-heated, debilitating, and ruined air.
  At that time I  myself was one of its zealous advocates.  I had
already noticed the universal complaints  of the occupants of rooms
which were heated by currents of  air from the common hot-air fur-
nace, but supposed it resulted from some peculiar effect produced by
the overheated iron, and, consequently, went energetically to work to
remedy these evils by warming all the air, by bringing it in  con-
tact with metal surfaces moderately warmed by circulating hot water.
  I persevered many years, inventing and patenting in this country
and  in Europe new and improved devices for accomplishing this
object, fully believing that a building, constantly overflowed with
this  mild, warm, summer-like air, must  be  the very perfection  of
artificial heating.
  And  yet  I was chagrined  and  mortified  that many sensible
people, with good independent judgment, would still  insist upon it
that they felt better,  their heads were  clearer and  brighter, in a
room heated by an open fire than in a room heated by my hot-water
apparatus.
   It was thus forced upon me, little by little, year by year, that
there wras a very essential difference between the room heated by an
open fire and one  warmed by currents of heated air.
  I was  just going to say I soon learned, but I didn't.  I slowly
learned that all warmed air was unwholesome and debilitating; that
it was not the manner of warming, but it was the fact of its being
warmed; that the sun itself could not warm  it  so as not to produce
this  debilitating effect, as witnessed  by the fearful  mortality when-
ever the  air in summer reaches nearly the temperature of  the body.
   In proportion  to  my convictions  of  the unwholesomeness of
warmed  air did I advocate the introduction of direct radiation-
first one-quarter,  then one-third  and one-half, and  perhaps some 
Plan of Treasury Building.
129
time I may believe in heating by radiation  entirely.  But there is
one practical difficulty about this, and  that  is, where the necessary
                               Fig. 21.
SOUTH WINC
PLAN OP U. S. TREASURY BUILDING.
air for ventilation is passed through the room,.and it is quite cold, 
130       Overflowing of Sewer into Fresh Air Duet.

it is so difficult to avoid unpleasant draughts; it requires very care-
ful diffusion.
  There is, consequently, less complaint of such  draughts when all
that  air is warmed, especially as all the occupants  are so stupefied
they have not much energy left to do  anything—not even to find
fault.
  But now to the examination of our building.  You will  see by
this plan that the building is a parallelogram, 480 feet from  north
to south,  and 260 feet from east  to west, with a connecting wing
between the two long sides.  I would just say that this hollow block
form seems to me to be very objectionable, as it completely cuts off
the through currents of  air, and it is frequently quite stagnant in
these inner courts when there is a pleasant breeze on the outside.
  You will notice there is a corridor in the centre, with rooms on
each side throughout the whole building.
  This section (see Fig. 16) is through the west wing.
  The hot-water coils for heating the  air are arranged along the
centre corridor, with the hot-air flues passing up the corridor walls,
and  the ventilating flues, what there are of them, are in the same
walls.
   The fresh air is supplied to all these coils by a channel under the
corridor floor, and directly underneath  this is a large sewer.   Now,
this was a very good place for the sewer as long  as everything was
perfectly tight, but I had strong suspicions it was not right, and one
day finding the workmen had taken up one of the large flag-stones,
I took a light and entered the dark, subterraneous passage, and there
I found a dreadful condition of things.
   When the cellar and basement were turned into  manufactories
they had carried the waste steam or blow-off pipes from the extra
boilers into the  sewer, and  the workmen had been careless about
repairing the breaks they had made, in consequence  of which, and
the  additional heat from escaping steam, with the badly cracked
walls, not only was the  foul, poisonous sewer-gas, heated up by the
escaping steam, pouring into the fresh-air ducts, but the whole sewer
had overflowed and filled this fresh-air duct with the filthy sewage
water, from 16 to 20 inches deep.
   It was not that deep, of course, when I was  in there, as it was a
dry time, but here are specimens (see Fig. 22) which I pulled  off
of  the scum and slime from water-closets, gutters, etc., which were
hanging from the sides and covered  the  bottom in thick layers. 
          DIAGRAM ILLUSTRATING
DEFECTIVE VENTILATION IN SOUTH WEST WING
          USTREASURY BUILDING. 
 
Cellar  Ventilated into Fresh Air Flues.          133
Here was  the  worst  kind of poisoning of the whole artificial air-
supply at its very source.
   It may be said this was not the fault of the original design but
its subsequent abuse.
   But I have  a very decided
objection to long, underground
fresh-air channels  under  any
circumstances.
   It is  possible, of  course, to
keep them  clean and sweet, but
in practice they are much more
liable to  become  damp  and
mouldy, and   worse—the re-
ceptacle of much trash, often
offensive, thrown there by care-
less or ignorant servants.
   If  you  are  not  already so
sickened that you cannot bear
it, I should like to give  you a
little  further description of the actual condition of this ventilating
apparatus.   You see  the heating chambers are arranged on each
side  of  the corridor, and for convenience in getting at the heated
coil, there  was a door about one foot square opening  from the
passage-way into the air-chamber under each coil.
   In  this cellar there were some  fourteen steam boilers in various
parts, with several  heavy  forging and blacksmiths'  fires, and an
innumerable amount of paint shops, etc.; and all  this was under a
fireproof ceiling, perfectly air-tight; and yet, with all this gas, and
smoke, and heat, this cellar was about the best ventilated apartment
in the building; and why ?—because they opened the doors into these
air-chambers and allowed it to flow in, and, mingling with the fresh
air! from the sewers, to flow up for the supply of the rooms above.
   N/ow, this is by no means an exaggerated statement of the condi-
tion of the air-supply of that magnificent building, with its  2,500
high salaried clerks.
   I took a little pains to ascertain the  effects of this condition of
things upon the employes, by  comparing the absentees  on account
of sickness with those from the Patent Office building for two or
three  months, which  showed an annual loss  of some twenty  or
thirty thousand dollars, a large  proportion of which would have
 
 134    Practical Lessons to be Taught by these Mistakes.

 been saved in dollars and cents, independent of the physical suffer-
 ing, by continuing the old-fashioned hickory fires.
   I found the physicians in the neighborhood had applied to the nu-
 merous patients from this building the term " Treasury poison cases.''
   The opinion prevailed to a considerable extent among the female
 employes from the warmer States, that the prevalent fevers in that
 neighborhood arose  from the  sewers  having become so polluted
 during the war by the proximity of several hospitals.
   I intended to have referred to each room separately—which I have
 numbered for that purpose—but having detained you so long must
 omit that.
   The practical lessons to be taught by this experience are—
   1. Never to have long underground fresh-air ducts.
   2. Never  allow a sewer, soil pipe, foul air-flue, or smoke-flue, to
 come near the fresh-air supply flue, for fear of some connection be-
 ing made between them by carelessness or by accident.
   3. Never heat a building exclusively by currents of warmed air.
   4. Always put the heating flues on the outside walls instead of in
 the inside walls.
   5. Endeavor strenuously to avoid the fresh-air chamber becoming
 a common receptacle for all the rubbish of a filthy cellar.
   You may think such mistakes in construction and such careless
 management of a large building very  seldom occurs, and therefore
 is entirely an exceptional case.
   It is not an exceptional case.  How many hotels can you go to, but
 what the first thing that  meets you on entering is the mouldy, stale
 smell, probably first of  the smoking-room, then of  the, bar-room,
 next some underground  laundry, then the oily smell and heat of
 the engine, and these interspersed with the odors of water-closets,
 kitchen, cockroaches, etc., etc., to the end of the chapter.
   Is there one of our large new printing establishments but what is
 saturated from top to bottom with the smells and heat of the engine
 and press in the basement ? and the halls of the establishment  are
 the actual ventilators of the boilers and engine house, just as  these
 halls of the  Treasury are the great ventilators for  that cellar and
 basement.
  No, my friends, you will find this is only too true an illustration
of a very large number of our  public and many private buildings,
and it is  time we acknowledged its truthfulness and set ourselves to
work in earnest to endeavor to remedy these defects. 
            DIAGRAM ILLUSTRATING
IMPROVEMENTS IN THE PLANS FOR THE VENTILATION
  OF THE NORTH WING U.S. TREASURY BUILDING. 
 
           Improvements Introduced into North Wing.       137

   Now let us glance for a moment at this section of the north wing
of the Treasury.   Here we have a combination of heating by direct
radiation  from hot-water pipes, exposed in  each room under the
windows, and a well-diffused supply of fresh air partially warmed
to prevent cold draughts.
   There are no underground fresh air ducts, but all the air is sup-
plied from windows above ground.
   The heating surface as wTell as the fresh air supply is all on the
outside of the building, and the ventilation is from the centre be-
cause the natural currents are from the outsides towards the centre.
   There is a good-sized flue for the ventilation of the boiler room,
and a separate one two feet square for the water-closets.
   The whole building is warmed by circulating hot water well dis-
tributed on the outer sides of the rooms, and although not entirely
perfect in all its details, as much of the materials for the building
had been prepared  before I was  called -upon by A. B.  Mullett,
the newly-appointed Supervising Architect, to give the plans for
ventilation and warming,  yet  it is so  superior  in  simplicity and
efficiency to the other portions of the building, as to give us much
encouragement that w^e are progressing rapidly in the right direction.
   The force of the current through the hot-air flues, as well as that
through the ventilating flues, is so rapid as to prove completely the
entire uselessness of the fan for forcing a current into  any such
building with well-constructed flues.

                        LEDGER BUILDING.
                        [View on the screen.]
   This  is a building I feel a great  delicacy in saying  anything
about.
   It is one of the most conspicuous, costly, and elegant buildings in
the city.  I have a very high opinion of the  intelligence  and lib-
erality of the proprietors, and  I believe they have not intended to
spare any pains in making the building as comfortable  as money
and the ingenuity  of man could devise.
  But they have almost entirely forgotten the supply of pure air.
  Gro on to that observatory and look over the roof, and you will be
puzzled to find one foot of opening for the escape of foul air.  The
architect  has  not  allowed that beautiful sky-line to be marred by
any tiling so nonsensical, as too many of them consider ventilators
to be. 
138     Improved Ventilation in Hospitals and Asylums

  They may say they have plenty of windows, but that is not the
thing.   We all know we can get plenty of fresh air by going out
of doors,  and opening windows is only equivalent to the same
thing.
  The engine room,  boilers, and printing rooms  are in the base-
ment, and I am inclined to think will cause much discomfort by the
unpleasant smells and heat arising through the building.
  Now, it is one of the easiest things in  the world  to  make that
waste heat, at the very bottom of the building, instead of spread-
ing over the building as a nuisance, do the work of ventilating the
whole establishment  splendidly, and I should be perfectly rejoiced
to see the proprietors of the " Ledger " ventilate their building in
a thoroughly  scientific and correct manner.
  Do you recognize that statue in front as that of the great Frank-
lin—the father of  ventilation—don't you think it must be a sore
grief to his spirit (if  spirits are cognizant  of things going on in this
world) to see  his image  thus fastened up  to public gaze in front of
such a badly-ventilated building as this 1
  Now, this is merely a fair specimen  of all  the great newspaper
establishments in the country.   I have  been  in  a great many, and
they are universally heated by  direct radiation from exposed  steam
pipes, and not the first foot of  ventilation provided either for sup-
plying fresh air or carrying off the foul.


                    HOSPITALS AND ASYLUMS.
  Perhaps in no other class of buildings  has there been  so  much
attention given to the  subject of ventilation as  in  our Hospitals
and Asylums.
  In many of these  buildings a good degree  of satisfaction has
been attained in this respect.  There are many  deficiencies, how-
ever, in these, especially with the very expensive artificial arrange-
ments.
  Much valuable  information was  gained  during  our late war,
although purchased at an enormous expense, in regard to  the con-
struction, ventilation, and management of hospitals, and  no point
was  more  fully  settled  than the  paramount importance  of  an
abundance of pure air  and sunlight for  the rapid  restoration of
those confined in them.
  This point  is now  considered of such great importance that it is 
Not yet Perfect.
139
scarcely considered admissible to build a double-roomed building;
that is, a building with a central hall and rooms on each side.
  Of  course, in some cases it becomes necessary, when very strict
economy is absolutely required in the first construction.
  This is a most valuable point,  too.  It  is now argued—and with
a good deal of  reason—that if by having only a single  room with
sunlight  and pure air poured in  on all sides, the patient recovers in
half the  time, which he will do, it is better to pay twice the price
for such  a building, than to get  double the number  of rooms by
cross  partitions, which obstruct the  free  flow of air.  This is  a
great  fundamental principle which ought carefully to be borne in
mind in  the construction  of all  buildings, dwellings  as  well as
hospitals.
  As  before remarked, I think we really have made considerable
progress  in the ventilation and warming of this class of buildings,
although in a very elaborately prepared work on hospital construc-
tion,  lately published  by Dr. Smith and  others,  after making  a
very critical examination of most of the costly engineering schemes
for artificial ventilation and warming, they condemn  them in most
emphatic terms, and by comparing the rate  of mortality in these
with  buildings heated  and ventilated  by the old-fashioned  fire
places, come to the conclusion that the problem of. properly ventil-
ating and warming our large public buildings is yet an unsolved one.
  I think they have some  good reasons for  coming to this con-
clusion.
  For instance, if  we take the new Marine Hospital  just finished
in this city (Philadelphia), a fine view of which we will now throw
on the screen, and a plan of  the heating and  ventilating  arrange-
ment  I will explain by a diagram on  the blackboard.
  Here  is  the  boiler-house situated  a long distance from  the
building, and in or near it there is  to be a fan for forcing all  the
air for the supply of the whole building through an  underground
air-duct to the farthest extremes of the whole building.
  In the cellar are the coils  of  steam pipes for warming the air
before it is throwm into the building, and from each  room, even to
the third story, I believe, are another set of flues for returning  the
foul air,  which it is proposed to drive clear back  again and  out
through a space around the engine  chimney.  And my impression
is that this space for the exit of  the foul air is much  smaller than
the aggregate of the flues entering it. 
140           Not Satisfactory in Marine Hospital.

   Here again are the foul-air flue and fresh-air duct running a long
distance together, with nothing but a thin brick wall between them,
and, like the Treasury sewer and fresh-air duct, will likely be per-
forated in half a dozen places before the building is long in use.
   Now it does seem to me  to  be  the' very  height  of engineering
nonsense to go so many hundred feet -down towards the banks of a
sluggish  fresh-water stream to get  fresh air, when purer and better
air is pressing upon every window with a force  of fifteen  pounds
to  every square inch; and can  you  imagine Avhy  it should  be
attempted to force that foul and warm  air  down  from  the two or
three stories of  this whole building  and  clear back to the engine
house, when any ordinary flue  would allow it to  escape quite  as
fast as  the fan would drive  it in, and by the simple application  in
those flues of  a small  amount of the heat required to drive the fan,
would  cause a  strong draught  at  all  times, summer or  winter,
whether the fan was forcing in the air or not %
   Here we have those objectionable  features of  long  underground
fresh-air  ducts, and  in direct proximity to the foul-air shaft, with
all the  air overheated, and no direct radiation, and attempting to
force or  coax all  the  foul air from the  various  portions of  the
building  so great a distance to one exhaust shaft.*
   * Since writing the above, and in the early part of 1871, I visited this hospital
to examine the practical working of the ventilation and warming.   The physician
referred me to the engineer; he informed me the fan was very seldom run except
on special occasions, when committees were visiting the institution.  After some diffi-
culty we succeeded in getting into the foul-air chamber around the engine chimney.
We found there a strong exit current.  But on examining the ventilation in the
various wards we found most of the ventilators closed; but there appeared to be an
entire absence of any current  either in the few that were open, or in the large
number we opened (15 or 20 probably) in various parts  of the building, both top
and bottom.
  I thought it was a little singular  there  should be no current, either out or in.
There  was certainly considerable  air passing out  the exhaust  chimney.  The
engineer thought it quite probable that there might be several openings between the
fresh-air and the foul-air channels, which the workmen might have made and omitted
to close up tightly.   I noticed also that in nearly all the heating chambers the door
was open for the purpose of getting the fresh-air supply from the cellar, instead of
drawing it from the fan room.
  Thus, the whole of this elaborate and expensive arrangement, like most similar
ones, when carefully examined was found to be almost entirely inoperative;  and with
all that fine show of ventilators, so liberally distributed top  and bottom, the poor
patients were not getting a breath of pure air which could be credited thereto. 
Asylum for Blind, Columbus, Ohio.

               Fig. 23.
141
  Now, in comparison with this we wull examine the plans for the
ventilation and warming of the Asylum for the Blind to be erected
at Columbus, Ohio.
  (I have  substituted  these  plans in the  publication  of these 
142
Ventilation by Heated Slmfts.
lectures  in  place of  some  others  used at the lectures, as  they
contain in a  more  condensed  form  the ideas designed to be
expressed.   The building is not completed, and the building  com-
mittee may not conclude to execute these plans, wholly or in  part,
but they were prepared at  their request merely as giving my ideas,
were submitted and paid for, and 1 have nothing further to do  with
the execution  of  the work; but  I use them to express general
principles applicable to all similar buildings.)
  This building is to have a forced ventilation by means of heated
shafts a, a ; but notice, if you please, the position of these shafts and
see how they are distributed in the various parts of the building.
  There have been many  attempts of late years to ventilate large
and irregular buildings by one grand central shaft placed at con-
siderable distance from the buildings.   Many failures and much
disappointment have resulted from such arrangements, and many
persons began to conclude that there  was no  dependence to be
placed upon  heated  shafts for the thorough ventilation of a group
of buildings.
  A heated shaft creates an exact definite force just in proportion
to the excess of heat of the air it contains over that of  the external
atmosphere,  and  its  power can  be calculated with just  as much
accuracy as that of the fan driven  by the steam-engine.
  For  economical working it is desirable that the currents should
move  slower  and with less pressure than is frequently exerted by
the fan.  Consequently it  requires much care  in  the  adjustment
of the inlet and outlet  flues.  Much trouble  frequently occurs for
want  of care in  making arrangements  to work with the  natural
movements of the air, and not against them.
  The additional pressure  of  the  atmosphere during a high wind
amounts to many tons, often hundreds of tons, on the windward side
of a large building, while  there is a partial vacuum created on the
opposite side.
  The supply for each room and the exhaust should be  arranged
independently for each exposed side so as to work in harmony with
these  natural forces, and then there is no difficulty whatever in its
perfect working at all times.  But with a single fan in  a central
position no such modification can be made;  it must be a uniform
pressure on all parts of the building, that is, at equal distance  from
the central force, consequently the rooms most favorably situated
will receive an over-due share, while in other portions of the build- 
Details of Fireplace and Flues.
            Fig. 24.


■A*

B Bffi M ill!
4-44
il
1^; ;
r
ii'
C2H
4#
T
T7-
Vr
/
2*
I     DETAILS OF FIREPLACE &. FLUES
    ASYLUM FOR BLIND  COLUMBUS, 0.
143
t        _____________________|
_j 
144  Combination of Radiation and Warmed Air Currents.

ing the force of the fan may be just equal to the external pressure
so as to produce almost perfect stagnation.
  It is always desirable to have as few horizontal air-pipes as pos-
sible, either for the supply of fresh air or  discharge of foul, but
where it is intended to apply  heat to  the  exhaust shafts  for the
purpose of forcing the  ventilation, it is more  convenient  to have
fewer of them, and consequently somewhat concentrated.
  I endeavor to avoid drawing the foul air  downwards  as much as
possible, because as it leaves the room when quite warm  there is
danger at times of a regurgitation, but sometimes  the construction
of the building or arrangement  of flues makes  it  more  convenient
to do so.   Then care should be taken to make  as  few openings  as
possible into the same duct.  In this case we take the coldest air-
that from the floor of first and second story.
  For the heating of this building I proposed about one-half of the
steam heated surface to be exposed for direct radiation in many
of the rooms and  passages, the radiators to be placed under the
windows so as to get the fresh  air  supply conveniently by raising
the window more or less as desired.
  The remaining half to be placed in the cellar for partially warming
a supply of  air at all times whether the windows were opened or closed.
  In addition to this the architect has provided  for fire-places in
nearly every room.  These will  answer an excellent purpose for
ventilation  even when not used for open fires.
  But in addition to these fire-places each room is provided with a
flue connected with one  of the heated shafts, with opening top and
bottom (see detail plan)  to insure a forced circulation at all times,
especially  in spring and autumn, when  it is too  cold to have the
windows raised, and yet not cold enough to have fire; forced ven-
tilation is then very necessary.
  It was proposed  to warm the whole of the corridor floors, which
would give an even gentle warmth to the halls and stairways without-
overheating the air.
  By thus warming the floors  the heat is retained where most
wanted—at the bottom; but when hot air is thrown into such halls
or corridors it escapes at once to  the ceiling, and frequently up the
open stairs  to the top of the building, without effecting much good.
  By having the floors warmed  in this manner  without  any projec-
tions or obstructions to the free passage of the blind inmates, these
passages would make good exercising halls in stormy  weather, as 
Ventilation of Churches.
145
they could have a free circulation of pure air by opening the win-
dows, and still retain a well-distributed  heat supply  at  the point
where most needed.
   The kitchen and bakery have each a large ventilating flue (A) sur-
rounding the smoke flue from each of these fires.  Also for the engine
room and laundry there is a large shaft around the boiler chimney.
   A building thus warmed  has  its  source of heat in each room,
entirely uninfluenced by the shifting course and varying strength
of external currents ; and so large a proportion being derived from
direct radiation, the rooms  may be filled with air  cooler than the
indicated temperature.
   If  the windows are all closed, there is a constant supply  and
exhaust for each room taken directly from the external atmosphere
without passing through any horizontal air-ducts (which are always
liable to become dirty and foul); or, by opening the windows, the
fresh air flows over the warmed pipes, and  passing in  its natural
course to the halls or  the  exhaust  shaft, merely adds to the more
abundant ventilation, without  danger of disturbing the  supply
of heat.
   It may be said, of course, that this building is  not completed, and
if these plans were executed, there might be as many failures as in
the Philadelphia Hospital or many of those buildings now completed,
the arrangements for the ventilation and warming of which were
anticipated to be so perfect.
   But the leading features here illustrated have been executed in
a large  number of instances within  the  last few years,  and have
given very general satisfaction.  And  to any one who  will take
the trouble to "think about  it" carefully,sthe correctness of these
principles will be perfectly evident.


                           CHURCHES.

  Here we have on the screen  a copy of a  photograph of a very
beautrf ul church near the  Falls of Schuylkill.
  Can you discover anything breaking that beautiful sky line that
would lead you to suppose its designers or builders had the slight-
est conception that  the moving machines  which  go out and in
there were breathing  animals,—that fresh air was  ten times more
important to them than food %
  I did not select this because there was any peculiarity about it 
146       Old Styles not Applicable to Modern  Wants.

in regard to the ventilation; it is  simply  an illustration of all
modern churches.
  I say modern churches; I  don't  mean that  they  are modern
designs.  It seems as though we have  no ideas of our own for
planning such buildings to suit the present needs and habits of our
                             Fig. 25.
FASHIONABLE CHURCH WITHOUT A PARTICLE OF VENTILATION.
people, but  must  copy from those old buildings made  several
centuries ago, even before chimneys were invented;  so that, if we
want a chimney, the architect says very emphatically, "You can't
have it;  it does not belong  to  the style."  But our modern  hot-
house plants cannot go to church for fear  of  taking  cold unless
the room is heated nearly as hot as an  oven ; so they have to resort
to some kind of deception, and frequently attempt to conceal a smoke
flue in one of the ornamental  finials. But their cheating is soon ex-
posed, and the reputation of the architect as well as the beautiful orna-
mental work is blackened by the smoke from the burning fires below.
  And as to  allowing the whole  design of  the building to be
utterly spoiled by  having a  great ventilator placed on top of it,
such a thing could not  be thought of for one moment.
  Now, I wish there was  some way of finding  an American with
ingenuity enough and  sufficient  independence to design an Ameri-
can building; and as we  must have,  as every  one knows,  several
fires in  such large buildings as most of our  churches, be honest 
Friends' Meeting-house not Warmed and Ventilated Correctly. 147

about it, and tell the truth by showing one or more good, substan-
tial chimneys, and in addition to that  to have an ample ventilator
or outlet for the foul  air.   I think such a man would soon earn
a  very  enviable reputation  among our practical, common-sense
people.
  We must admit, however, that  there is also something to be
learned  by the rest of us—the architects are not entirely to blame—
as,  for  instance, we find some mistakes even in a new meeting-
house, built by Friends at Germantown ; there they were not troubled
by architectural rules.  One  of the  special reasons for abandoning
the old building and erecting a new one was to accommodate the new
idea that had just begun to dawn upon the minds of  the people, that
it was necessary to have ventilation, even in a meeting-house.
  Each  member of the  committee, therefore, as is usual  in such
cases, I  suppose, felt it  his special duty to devise and  urge a new and
valuable improvement in ventilating meeting-houses.
  Although each  one might be entirely different from any of the
others, yet they would  be urged with no less earnestness  and  confi-
dence,  owing  to  their being  quite new  (all plans  for  artificial
ventilation, except the  open chimney, are necessarily new).
  Well, the house  was ventilated, and quite a liberal allowance of
ventilators were displayed all around the sides, top, and bottom, and
all led into a conductor behind the cornice which was carried to the
chimney ; but it was a real, honest chimney, however.
  (It wyas  suggested to me  that the  size of this flue behind  the cor-
nice, for receiving the air from all the  other flues, was only half  of
one square foot on each side.)
  Now, this committee thought they were going to have one of the
best ventilated buildings in the world, but just imagine their disap-
pointment for the  first time it was occupied on  a cold day, to find
those persons near the ventilators shivering, and putting on their
overcoats  to protect themselves against the cold draughts from the
open ventilators.
  They had made the  very common mistake of  locating the  venti-
lating flues in the  cold outside wall, and in frosty weather the air in
those flues being colder than the air in  the main part of the build-
ing, it of course would fall down and pour out into the room.
   They also followed  the inclination of all heater men, and, prob-
ably, the advice of the one that put these heating registers in the
centre of  the room, instead of around the outsides;  consequently, 
1-iS         Illustrations of Incorrect Ventilation.
those in the centre would be suffering with heat and foul air, while
the ones on the outside were complaining of cold.
  Our whole practice of ventilating and warming such buildings is
about as incorrect and unscientific as could be well imagined.
  To have a large building closed up several days of the week, until
the walls and floors get thoroughly cold, and then a few hours before
the assembling of the people to build a fire in an old rusty furnace,
throwing in a stream of highly heated air until it gets warmed down
a little below the heads but leaving the floor and feet cold, so that
the occupants must breathe warm, debilitating air, while  the wralls,
floors, and furniture are rapidly absorbing the animal heat from the
body, are conditions  very  unfavorable for sound,  active, mental
exercise.
  They are stupefying.
  And, again, to place the  heaters  in the centre of the building in-
stead of on the outside is erroneous.
  Let  us endeavor to examine by this diagram on  the blackboard
(see lithograph, No. 18) the movements of the air in such a room.
  I say let us examine these currents ; we cannot see them, of course,
but if  we would only think a little every person here must  know
almost precisely the movements of the air in such a room, under
certain well-known conditions.
  We all know, for instance, that each human body is  98° at all
times.   If the blood falls a very few degrees below that life  is ex-
tinguished ;  so do we know that the air from  a hot-air furnace very
commonly rushes into a  room at temperatures ranging from 200°
to 300°, and by watching the particles of dust, etc., we see that this
air rises immediately to the ceiling and spreads out there.
  We also know there is a strong descending current of cold air
under windows and along cold outside walls ; this air sweeps  back
along the floor, and again rises near the centre of the room.
  Now, suppose there are twenty-four persons sitting side by side.
You see at commencement the first one would have quite pure air
to  breathe, the  second not so pure, the third one would have to
breathe soiled air—the air that had come from the lungs of the first
and second, and  that  which  had swept  over  their bodies and
absorbed  the exhalations from them.   The fourth one would  have
to breathe foul air, the fifth very foul, and the sixth, well,—I hardly
know what  to say,—I want you to stay with me until the close of
the lecture, and  I don't think it would be best to attempt to describe 
An exagerated representation of the relative temperature
and movements of pure and fouled air in a well filled room,
heated by air from, a furnace opening into the centre of the room 
 
St. Ann's Church, Brooklyn.
151
what those poor victims at the other end of the seat must have to
breathe.
  Now, we all know this is just the condition of our large halls, when
they are well filled. We also know how we suffer with heat and op-
pression when we are in the centre of the room, and yet how chilly
it is near the windows.
  Or  in summer we have  noticed how warm and foul it was, even
in the open  air, if we get near the centre of  a large number of
people ; or in crossing the river on a steamboat, when it  is quite
crowded, I have noticed, by standing four or five  back from  the
front, it would  be  quite oppressive, even with a brisk breeze blow-
ing in front.
  Notwithstanding we are all aware of these things, yet here is  a
committee of  as  intelligent  men  as  you  will  commonly find
associated  together,  and yet these men, like  most others, when
it comes to ventilating such a building, seem to take leave of their
ordinary good  judgment, and  allow such awkward, incorrect, and
unscientific arrangements  as these  to  be made,  and will allow
themselves and their families  to  be annoyed  and poisoned, year
after year, rather than to make a determined effort  to remedy it.
  The very common fault of taking the air for the furnace directly
from the cellar, without any fresh air box, is practised here.  If  the
window is opened  to let in fresh air, this cools the whole cellar, and
consequently the floor of the room above, instead of which the cellar
ought to be shut tight and heated hot, so as to warm the floor above,
and a separate  box  should be provided  for the supply of fresh
air.
  As  an improvement upon this I have  introduced a section of

                  st. Ann's church, bkookltn,
showing the manner of ventilating  and warming that building.
  (These plans were  not  used  in  the lectures, as  they have been
made since.)
  The whole building is heated by low-pressure steam, and, as will
be seen by  reference  to the  accompanying  lithograph,  all  the
heating arrangements are placed on the sides under the  windows,
and in this case the fresh air, for the main audience room, is admit-
ted over the head of the basement windows, and, passing over the
steam pipes, enters the room well diffused along the whole side.
  Those in the main audience  room are  screened by a  cast-iron 
152
Well Warmed and Ventilated,
wainscoting, perforated at the top for the outlet of the fresh air.
This warms the whole side  of the room near  the  floor, as well  as
gives an abundance of fresh air.  By perforations  in the ceiling of
the galleries, the warmed air passes through the upper angle of the
galleries and behind the wainscoting, where there are three addi-
tional pipes ; and this warmed air rises by the upper windows and
completely cuts off  those  cold descending  currents from the win-
dows.
  By a series of carefully tried experiments, with ten thermometers
hung at equal intervals across the whole room, there was not three
degrees difference;  those close  by the  heating  apparatus, on the
outside, were about  two degrees the highest, but this would be com-
pensated for by the  greater loss  of heat by radiation from persons
sitting near the cooler windows, so  that  it might be  considered
almost exactly  equal.
  By furring dowm  the basement ceiling  five inches, a space was
secured for the escape of the foul air from the ceiling .of the base-
ment, and from the floor of the main audience room from each pew.
  These foul-air ducts are carried  to the towers  in front, in which
are steam coils  for insuring a greater draught.
  These exhaust-shafts are five feet square each, giving an area  of
fifty square feet in the two.
  I was quite  desirous of having the heating  pipes placed  imme-
diately under the basement floor, for the  purpose of warming the
floor of that room, but owing to the difficulty of sinking the boilers
sufficiently to return the condensed water, this was not done, but
the pipes  were placed under the windows on the outsides, which
answers a very good purpose, but not  quite equal to having the
floors warmed.
  It will be noticed  the process  of warming the room  is entirely
different from the previously described meeting-house.
  In that  case all the warmth was derived  from the introduction  of
currents of warmed  air.  These raised  directly  to the ceiling and
spreading out horizontally, crowded the  colder air  down, and so on
until  the whole room was filled with warmed  air.   In rooms thus
warmed it is often  excessively hot at the top  and in the galleries
before the warmth begins to be felt on the floor ; but with this it is
quite different—the heating surface being directly in the room itself.
the heating commences at the bottom, and it may be quite hot there
before it is warmed  at the top. 
 
 
         But not entirely Automatic / still Needs Care.      155

  The first winter the building was used there was complaint of cold
draughts in the centre of the main audience-room, and on careful
examination I found it was only in commencing the heating as the
cool air from above descended to take the place of  the hotter.
  For instance, when  the whole room was 35° on turning on the
steam, the effect was felt at once under the galleries, so that it was
soon comfortable there; but, of course, as the warm air rose the
cold air tumbled down to take its place, which gave the thorough
agitation and revolving motion to the whole mass, just as putting fire
under a pot of water sets the whole to revolving.
  But when the whole air in the room gets heated to 65° all incon-
venience from these unpleasant draughts disappears.
  As superior as these arrangements are to the ordinary methods of
warming  such buildings,  they do not obviate the  necessity of
commencing the fires a few  hours before the gathering of the
congregation.
  As the immense  height of  this building, with its three rows of
windows on each side, and large, exposed roof, cools the air so
rapidly, it is impossible to heat this great mass without the expendi-
ture of a large amount of coal; there is therefore a strong temptation
to economize as much as possible in this particular, at times, perhaps,
to the inconvenience of the audience.
  But I believe under  no condition whatever is there any complaint
of foulness  or stagnation of the air, either in the  main audience-
room or in the basement; and when care is taken  to commence in
time to have the whole of the  air warmed to 65° or 68°, the whole
building is as perfectly comfortable and satisfactory, both for warmth
and ventilation, as could well be desired, even when crowded.
  There is a very simple way of making many buildings much more
comfortable than they  are usually; that is, by heating them to 80°
or 90°, so as to warm the walls and floors and all solid objects in the
room to that temperature before they are occupied, and then allow
the  fires to  go almost  out, and supply the air cool and fresh when
the  congregation assembles.
  But we shall have to wait for a new generation of care-takers or
sextons before this can be hoped for.
  I know of no more entirely hopeless undertaking than to attempt
to convince  the sexton of a church of the propriety of heating up
his building so long beforehand, and then to let the fires slacken on
the gathering of the congregation. 
156    Modification of Flues at  Westtown Boarding-school.

  They are as thoroughly impervious to all argument on the subject as
any class (»f men in the world, except, perhaps, sleeping-car attendants.
  We have here the plans (only  part have been introduced here)
for  the improvement  of the ventilation and warming at
westtown boarding-school.
Fig. 26.
         PLAN AND SECTION SHOWING MODIFICATION OP FLUES AT WESTTOWN.
  I wish to call your attention particularly to the manner of util-
izing the old fire place flues. 
One Flue Used for Several Stove-pipes.          157
   Open hickory fires were used when the building was first con-
 structed, but these good old ways of our forefathers were aban-
 doned for those modern nuisances, hot-air furnaces, and the old fire-
 places were walled up with much care.
   Some time after a fever breaking out, and becoming so alarming,
 the school was closed  and children sent  home, and the building
 examined with a view to the improvement of its ventilation.
   We thought it desirable to utilize these  old flues for ventilation,
 but in many of them  it was necessary to have a stove-pipe from
 some of the upper rooms.
   Now, it is not good to open a ventilator in the same flue  that is
 used for smoke, because by letting a rush of cooler air into a smoke
 flue the draught of the fire is very much  interfered with, and the
 smoke from  the fire may at times be blown out or the soot might
 fall down and soil  the carpet.
   Should such a thing occur one day out of the 365, it would be
 condemned very likely as a ventilator  and  closed up.
   But to avoid these  objections you  see we hit upon the happy
 expedient of using the  basement flue  exclusively for a smoke-flue,
 and .turned all the smoke-pipes into it,  thus liberating all the others
 which are used for ventilation.
   It may be  asked if it is a good plan to turn several  smoke-pipes
 into the  same flue. Within certain limits, each additional stove-pipe
 would increase the heat of the flue.
   These flues  being 13 inches square would have an  area of 169
 square inches; this would be  equal to 6 or 7 ordinary stove-pipes,
 as it takes but a small  amount of air for an anthracite coal fire in a
 stove.
   The case is quite different, however, with an open fire or a wood
 stove, which requires a larger flue.  Several fireplaces opening into
 one flue in this manner would be  likely  to interfere with each
 other.
   For open fires it is better to have separate flues for each, to avoid
 the gas and smoke from one being blown out of  the others by sud-
 den gusts of wind.
  This building is a good illustration of  how great changes in the
sanitary conditions with which we are surrounded may  take place,
but so gradually as to be almost unnoticed by us.
  Some of the older Friends, who remembered with pleasure  the
happy days of their childhood  spent at that school, remonstrated 
15S           More Sunshine • less Shade Wanted.

quite energetically against the new-fashioned ideas about ventilation.
It was good enough for them, as they were always  very  healthy
there, and they did not see why it was not sufficient for their grand-
children.
  They did not approve of spending so much money on these new
things, but they entirely overlooked the important fact, that with
the original open fires there was more ventilation in one room than
was now provided in ten rooms for their grandchildren.
  And  again,  these  rooms  were   now  supplied  with  air  for
breathing which frequently came into  the rooms  at 200° or 300°
(most debilitating stuff), while the air they  used to  breathe  was sel-
dom over  40° or 50°, and the warmth they received was from  the
pure rays of the open fires.
  Another great change had taken  place by the overshadowing of
the building by the elegant trees surrounding them.
  In its earlier days when first built upon those  beautiful hills, the
bright  golden rays of sunshine bathed and permeated the whole
house, thoroughly disinfecting and  purifying it from cellar to  gar-
ret, and no  doubt this  influence was strikingly reproduced in the
sparkling eyes and glowing radiation from  the cheeks of all the in-
mates.
  How changed now.
  With the sun several hours high, there was that dark, gloomy feel-
ing that made me feel sad; and as I looked at the few puny bleached
flowers in some of the  windows which were struggling for existence,
just  kept  alive by the few stray sunbeams  that now and then stole
through the dense foliage, I determined to  make one vigorous  ap-
peal  for a little more sunshine.
  But  oh! what a stir  the dear Friends made when it was  pro-
posed to cut down those beautiful  lindens that their fathers had
planted and had been nursed with such care, and worse yet when
those magnificent  firs were marked out as more than useless in-
cumbrances of the ground.
  A few of the lower  limbs were trimmed  out, but not one-quarter
enough.
  I was very much pleased with the striking contrast to this sunless,
gloomy picture on visiting soon after  the Juvenile Asylum, on
Washington Heights, New York.
  On approaching the building, although in winter, we  noticed all
the windows of the  dormitories were  open, and I  think  there is 
                 Public Schools,  Philadelphia.              159

not a single leaf of a tree allowed  to cast its shadow on any part of
the entire building.
  It was  very pleasing to  learn  that there had been but 2 deaths
in 5 years in a family of 600 children.  Many of these are picked up
from the gutters and streets of New York—mostly from that tene-
ment-house population that furnish so large a portion of early
deaths.
  There are a few hours in the middle of the hottest days in sum-
mer when the shade of surrounding trees may be advantageous, but
there are many more  hours  in the year when it is both agreeable
and of very great importance that we should  have  all the sunshine
we can  get in our rooms.
  I think this want of sunshine is often the cause of much sickness
and lack of vigor.  *

                PUBLIC SCHOOLS OF  PHILADELPHIA.
   On the  Screen  (see Fig. 29) you have the plan of  one of the
elegant new school-houses of this city.
  Please  be kind enough to apply to it some of the principles we
have been studying, allowing me just to remark that there is scarcely
any place that requires such care in arranging the ventilation  and
heating as in school-houses.
   The young, active, growing brain demands the  purest and  best
air, and is the most sensitive to any foul.
   The same remarks that applied to hospitals are applicable in a
special manner to  school-houses.
  As nearly as possible each class-room  should open freely to the
fresh air and sunlight  on every side.
   Instead of which it  seems to have been the study of those plan-
ning these buildings to mass all the class-rooms as much as possible
and to  surround them with stairs, committee-rooms, etc., so as  to
cut off  a large proportion of the most valuable exposure for light
and air.
   Not contented  with this great  isolation  from the external  cur-
rents and  sunshine, they are  again subdivided by glass partitions
which most perfectly cut off all through draughts.
   Supposing the wind to be blowing in the direction indicated by
the  arrow, how completely those in  the second  and third rooms
would be deprived of  the benefits of these external currents!^
   I wish there was some way of picturing clearly to your vision,  or 
160
Plan of School-house
perhaps I should say to the vision of the Public School  Commis-
sioners, how poisonous and foetid that air is as it oozes through from
                              Fig. 29.
PLAN OF NEW SCHOOL-HOUSE, PHILADELPHIA.
the first class-room  to the second, and yet still worse  as it passes
from the second to the third. 
Not Good in a Sanitary Point of View.         161
  The air becomes very foul in the first room, much fouler in the
second, and—well, what should I say for the third ?  I don't like to
use that  homely English word that would express it, I am afraid
you would not think it delicate, but I do not think it half so bad to
use such words as it is to build such buildings and force our chil-
dren to breathe over and over such stinking air.
  I do not believe, since children commenced learning their A, B, Cs,
there were ever  erected such a splendid set of school-houses in
which those great fundamental principles of sanitary science, sun-
light  and a free circulation of air, were set at defiance in such a
reckless manner, and  yet we are going right along, spending hun-
dreds of thousands, and I suppose millions, in erecting these costly
and  elegant—well, what shall I call them ?—if they are used for
packing  our  children  in and poisoning and smothering  them to
death, would Slaughter Houses be a proper term for them ?
  You may say, " Oh, well, it is not intentional,—these gentlemen
don't know any better."  Not intentional!—but how much care are
we taking to  avoid it %
  If  your physician was to make a mistake in his spelling, or from
a misunderstanding of its effects give  you a prescription  for a vio-
lent poison by which  the whole family is sickened, would you ex-
cuse  him by saying it was not intentional, he did not know any
better; would you be  likely to continue to  employ that physician,
or would you endeavor to get one who  did know better ?
  If  you were to go  to any of these School Commissioners to urge
upon them  the necessity  of improving the ventilation  of these
buildings they would scarcely have patience to listen to you five
minutes, and they would be likely to let you know very soon, if they
did not tell you directly, that they did not know anything about that
thing, and they thought ventilation a good deal of a humbug anyhow.
  Now,  how long  are we to submit to this plea of ignorance as
a justification for this  great amount of suffering and unnecessary
death, where every week's report of  the Board of Health contin-
ues year after year to  tell the same  sad story, that  half the deaths
in the city are  caused for want of ventilation ?
   It is not a  difficult matter so to  arrange the class-rooms that they
shall be exposed to the sunlight and fresh air on all  four  sides of
each room, and further, that each room shall be so separated that the
air from one room shall not pass into another.
   We <rive here a plan embracing these characteristics merely as a 
162    Suggestions for a Sunned and Aired Scltool-house.

suggestion, which of course would  be modified to  suit different
localities.
                             Fig. 30.
PLAN GIVEN AS A SUGGESTION FOR A SCHOOL-HOUSE, WITH LIGHT AND AIR ON FOUR SIDES OF
                        EVERY CLASS-ROOM.
  There might be objections to so many windows by some of our
fashionable ladies who have been accustomed to groping about  in
the dark, and who have their blinds  all closed  and curtains down
for fear of a little sunlight finding  its way in, which might fade
their  carpets; but  as we are rapidly  learning that  the want of
sunlight fades our  children's  cheeks as much as the  sunlight does
the carpets, I hope but  a few years will be required to give us a
wholesome dread of all rooms not abundantly purified every day by
Nature's great purifier, sunshine.
  The excess of light would, of course, be regulated by blinds—cur-
tains  are not  suitable, as they obstruct the circulation of air, which
is needed in warm weather, and  the  blinds, wrhen turned, obstruct
the light, but allow a free current of  air, which  is directed towards
the ceiling and falls gently diffused over the room; and these should
be green, if the architect would allow it, as that is the most pleasant
color  for the  eyes.
  As light is thus admitted on four sides, it might be shaded on two 
Good Provisions for Artificial Ventilation.        163
sides when the glare of the sun was objectionable, and still leave
two sides fully open.
   The heaters should, of  course, be placed on the  outsides, and if
steam or hot water circulation is used,  the  radiators should be
placed under the windows.  With our present patterns of stoves
they could not so conveniently be placed there, but might be placed
near by, and well supplied with fresh air direct from the outside.
   Now, notwithstanding windows are so indispensable for a school-
room, yet they alone are not sufficient at all times.
   Some artificial power is needed to give a positive motion to the
air on still, warm days, and nothing seems better for this, even for
a school-house, than the heated shaft.
   It will  be seen,  by reference  to  the plan, these come in very
nicely in  the centre of the building where they  should be, and
where they are easily accessible from each class-room and  closet.
   A well-diffused ventilation  is secured  by having a  number of
registers in the floor, and using the space between the joist as foul-air
duets, and by lowering the ceiling of the closets and teachers' room
the foul air can be carried across the joist to the foul-air shaft; the
shaded portions on the plan  show the direction of the foul air.
   If required, one  shaft can  be. made to answer for the whole
building, or they may be carried up separately and connected under
the roof.
   Where steam is used for heating, a coil in the shaft causing the
necessary draught, and a stove at the bottom in warm weather, is
probably  the cheapest and  simplest  power  easily attainable  for
such buildings.   For the escape of foul air, there should be liberal
openings near the ceiling, as well as from the floor.
  When a large  proportion  of  the heat  is  from direct radiation,
these can be left  open most of the time.
  To insure perfect  success  in  a crowded school-room, it is neces-
sary to make ample  provision for the circulation of a large amount
of air.  I have in many cases allowed one  square foot area of ven-
tilating shaft for each ten children.
  This probably is a little larger than would be positively required
if the shaft was kept sufficiently heated  to  insure a  strong draught;
but the failures in such arrangements very often result from want
of capacity.
  For the  large  exhibition  room, now considered  so essential by
main- school boards, one-half of  the third story might be readily
             10 
104
17/ Hadvlph ia  Cottages.
adapted, by omitting the partitions and extending the floor over the
recess (by a Mansard roof, for instance); the ventilating flue could
be carried across the hall and  connected with the other flue in that
case.
                    PHILADELPHIA COTTAGES.
  We have here' a copy of a photographic view of a row of houses,
the peculiar  feature of  which  forms the  very  strong contrast
between Philadelphia and  New York—and,  in  fact,  between
Philadelphia and almost all other cities in the wTorld.
  These small two-story houses, which form the dwellings of so
large a portion of Philadelphians, each room having a large window
                             Fig. 81.
and generally a fireplace (I only wish they were open), are scarcely
equalled in a sanitary point of view  by any  other houses for a
similar  class of  men in the  world,  the  Peabody dwellings  of
London,  the Emperor  Napoleon's  improved  homes, or Prince
Albert's model houses not excepted.
  It is this peculiar feature  of  the homes of her industrial classes
that  makes Philadelphians  so much  more  healthy than  New
Yorkers. 
New York Tenement Building.            165
  The situation and natural surroundings of this city are less con-
ducive to health than those of New York.
  But let me read here a few lines from a late number of the New
York Tribune, describing the tenant-house life in that city:
  "A person who has never seen a New York tenant-house can form
no idea of them.  They are usually eight stories high, including the
basement, and built two on a lot which is only 100 x 25 feet in size.
  " The basement is usually crowded with families, and sometimes
the cellar underneath, lying below high-water mark, and  frequently
flooded by the tide, swarms with squalid women  and children bur-
rowing in miasmatic lairs.
  " A hall about  Z\ feet  in width runs through  the centre of the
building, dividing it  into two tiers of apartments on  each floor
from basement to attic, and these apartments  are  subdivided into
front, middle, and rear, making six suits on each  floor.
  " The first floor fronts are often used as low groggeries, with  the
families of the owners living in the rear of them, and the remain-
der of the building is packed six families on a floor to the roof.
  " These houses  are sometimes built twice, and even thrice, as deep
as the one we have been  describing, with six, and even eight suits
of apartments on each side of  the hall, making from 12 to 16 suits
to a floor.
  " The expression, ' suits of apartments,' will be  certain to mislead
the reader as to the  real  character of the rooms  in  which these
people live, without a special statement  on  the subject.  They
should really be  called sets of dens.  They usually consist of two
rooms—a living-room  and a sleeping-room; the  first  being  about
eight feet by ten,  and  the second seven feet by ten, and averaging
seven feet  in  height.  The bed-rooms have no ventilation except
what they  get through the door  opening from the  living-room,
which  has  no ventilation or  light except what it gets through the
door and window opening into the narrow hall.
  " This so called living-room is used to cook and wash in, and is
also frequently used as  a shoe shop, tailor's  shop, and for other
manufacturing purposes.
  " Not unfrequently two families, and even four, live  in one  of
these  small sets of dens,  and in this manner as many as 126 fami-
lies, numbering over 800 souls, have been packed into one building,
and some of the families taking boarders and lodgers at  that.
  "Around many of these tenements, or in close proximity to them, 
166
Interior View—rather Bad.
are slaughter houses, stables, tanneries, soap factories,  and  bone-
boiling establishments."
  For further illustrating the subject, I have introduced here copies
of the plans  and a section of a tenant-house on the rear end of a
lot on Mulberry Street, near Chatham.
  I had these made for the " Technologist" for February, 1870.
  The artist in making his sketches visited each story,  surrounded
by a crowd of inquisitive and rather belligerently inclined spectators.
SECTION OF A NEW YORK TENANT HOUSE.
For a further description of this building, and an account of the high
rate  of mortality among its inmates, see the above-mentioned journal.
  What a contrast!
  It seems a little remarkable that two cities so close together, with 
        Difficult to make Perfect without Tearing Down.    167

such  frequent communication  between  their inhabitants, should
have adopted styles of  buildings  so  entirely different.  But the
great dissimilarity is probably owing to the respective peculiarities
of  the ground on which they are built.
   Philadelphia had the opportunity of spreading in all directions
from the original centre.  New York, having commenced on the
-extreme end of a narrow neck of land completely surrounded by
water, its expansion was confined to this narrow strip in one direc-
tion, hence the temptation to the excessive crowding found there.
   Now, it is a very difficult matter to improve, or, I should say, to
make  the ventilation perfect in those great masses of buildings in
which more than half of the New Yorkers live, and of  course it is
 entirely impossible to get the direct rays of the sun into those dark,
 gloomy bedrooms, the walls  and furniture of  which must be  con-
	—'	I
\—		—f
PLAN OF A NEW YORK TENANT HOUSE,
stantly absorbing and becoming more and more saturated with the
foul, foetid poisons of human exhalations.
  And, as the intelligent  sanitarian but  too well  knows, these
unsunned and unaired rooms become veritable pest-houses, distrib-
uting and dealing death and  dismay to the poor, unfortunate, and
often ignorant occupants.
  But, my friends  of Philadelphia, you  are  neglecting to secure
much of the advantage that is thus placed within your reach.
  Whv were there 6,000 deaths caused in this city last year by foul
air, and 2,000  deaths  by consumption ?   Consumption, that purely 
 168 Philadelphians not Making the best Use of their Advantages.

 foul-air disease, a complaint so common and yet so entirely and so
 simply prevented; a disease that is as true an indication  of the
 breathing of filthy air as the itch is of the uncleanly habits of  its
 victim.
   A visit  to a  few of these houses will  answer these questions
 readily.  Although their external form and general  plan greatly
 favors the health of the inmates, yet you will find an entire absence
 amongst the occupants of  any intelligent appreciation  of  these
 advantages, or  any effort  on their  part to provide  an adequate
 supply of pure air; you will find nine out of ten, or perhaps nine-
 teen out  of twenty, closed just  as  tight as the ingenuity of the
 occupants can make them; and with  the  perfection with  which
 doors and windows are made  to  close nowadays, the chances are
 small of  an adequate supply of pure air stealing  in  through such
 cracks.
   Almost every fire-place wull be found closed by a fire-board, with
 a neat picture over it sealing it air-tight.
   And to cap the climax, you will find the room heated by that
 object so much dreaded by foreigners—the American stove—a little
 air-tight  stove—a stove too small for the room, but the deficiency
 in its size made up by heating  it white hot instead of only red.
   Not one  in one thousand of these stoves will have any fresh-air
 supply,  and but few of them will be provided with  water for
 evaporation.
   Now, put a number  of  people in such  a room as this with a
 smoking  lamp—and worse, a smoking tobacco-pipe—heat the same
 air over and over, and you will have a room that not only a foreigner
 but any intelligent American ought to dread.
   It is here a great reform might  be inaugurated  so readily and
 carried forward, by inducing these people to unstop the  fireplaces,
 sleep with  their windows open, and, with but little more trouble,
 each stove might be well supplied by fresh  air  through a space be-
 tween two joists, and carried to the top of the stove.
   We will  throw a view of Paris  on the  screen,  and  from the
 immense number  of  chimneys seen on all the  houses,  you  can
readily understand that an essential of every room for a Frenchman
is a fireplace ; and when we know that they use them for  building
fires in, instead  of  back-grounds  for pictures, it is easy to compre-
hend why they are so oppressed in such a close stove-heated room as
 described above. 
Old-fashioned House well Ventilated.
169
  Now, notwithstanding such  a  close stove-heated room may be
made so uncomfortable, yet I am a great advocate of the stove,
when used properly.
  (See article from Manufacturer and Builder, page 189.)
  We  will now throw on the  screen a view  of  an old-fashioned
house, wdiich is a complete refutation of the idea, often expressed,
                             Fig. 34.
.-FASHIONED HOUSE, SHOWING MORE VENTILATION THAN A WHOLE BLOCK OF MODERN
                          HOUSES.
that ventilation was a new notion.  But  the fact is, as you see by
these great ventilating stacks used as chimneys, there was more ven-
tilation  in  one such  building as this than in  a whole block  of
some of our very modern houses.
  It is the close and tight room that is the modern invention. And
now, let us  resolve to "think a little"  about the  very important
subject of supplying our buildings with pure air, and a comfortable
genial warmth.
« 
% 
Ventilation.
THE GRAND PRIZE AWARDED AT THE PARIS EXHIBITION.
   Added to the many other gratifying signs of a rapidly increasing
 interest in the all-important subject of the proper supply of pure air
 to our houses, is the awarding of the grand prize of the Paris Exhibi-
 tion to Dr. Evans,for an American sanitary collection.
   The Sanitary Commission, during  our  late war, acted upon the
 principle since  expressed  by the  report of the Board of Health of
 New York.   They say^   " And viewing only the causes of prevent-
 able diseases and their fatal results, we unhesitatingly state  that the
 very first sanitary want in New York  and  Brooklyn is ventilation
 —ventilation supplied  in  all existing  tenant-houses,  work-rooms,
 school-rooms and places of assemblage—and  in all that shall here-
 after be constructed."
   The early recognition during  the late war, both by the Sanitary
 Commission and the  government  officials, of the important fact that
 many more  men are killed by breathing foul air than are killed by
 the  enemies' bullets, led them to use very active exertions to secure
 good ventilation in  hospitals and camps, and to teach the men them-
 selves the value  thereof.  The result  has  been highly satisfactory.
 The fact that we must  make  some positive provision for a constant
 supply of fresh air to every occupied room, and not rely on accidental
 cracks and openings, is now very  generally felt.   The simple, prac-
 tical and efficient means used by the government has done much to-
 wards creating this wholesome public opinion.
  The annexed plan (excepting a stove and twelve beds, omitted from
 centre of plan, indicated by the space)  is a copy  of one I furnished
the Committee; and which was faithfully executed in preparing one
of the models of hospitals, the arrangements of which have  been so
highly appreciated,  and has shared one of  the grand prizes  at  the
Paris Exhibition.
  It is a representative  plan,  showing the  general arrangements of
wards in a large number of the hospitals. 
172
Plan of Hospital.
■m
JKazs-*
   The  special  arrange-
 ments of flues, v, for win-
 ter ventilation, and the in-
 troduction of the fresh air
 around the stove, were not
 introduced into the hospi-
 tals in Philadelphia, built
 at  the commencement of
 the war.   And the subse-
 quent orders of  the Sur-
 geon General and Quarter
 Master  General for  the
 introduction  thereof were
 protested against by  the
 Surgeons of Philadelphia,
 owing probably partially
 to  their  proverbial   ob-
jeetion to changes of any
 kind,  and   partially  to
 that  dread of "ventila-
 tion" made but too popu-
 lar by the many erroneous
 theories which  propose to
 introduce  the  fresh  air
 directly  into  the  room,
 and at times, too, when it
 is even below the freezing
 point, without first warm-
 ing  it.  These arrange-
 ments, shown in the  ac-
 companying plan and sec-
tion, were thoroughly test-
 ed, however, in many of
the hospitals subsequently
built in many of the West-
ern cities.
  The plan of ridge venti-
lation, shown in the accom-
panying section, I applied
first in St. Louis, in the
summer of  1863.   It is 
                       Section of Hospital.                  173
      t   •
the principle of the Emerson ventilator applied to ridge ventilation.
Much trouble had been experienced with  other forms on account of
their allowing the storms to beat in,and the  difficulty of opening and
closing them with the various changes of wind; this form fully remedies
those objections, and can be left open withoutinconvenience at all times
while snowing or raining. It uses the force of the wind,whenever there
is a current passing over the top of the buildingfor sucking the air out
of the ward,  because  the air  in passing across the top of  the build-
ing is deflected from the straight line by the angle of the roof-board,
which creates a partial vacuum in the space below, which, with the
friction of the passing  current  with that coming  out of  the ward,

                              Fig. 36.
makes an outward draught, varying in proportion to the velocity of the
external current.  This is often very useful, especially in summer,
when there is not sufficient difference between the external air and
that in the ward  to create a current.  There is often a considerable
force in the passing current at the top of the building when there is
much less below.
  But of course these openings had to be closed in winter to prevent 
 i 74                   Ridge  Ventilation.
                                                          \
all  the heat from escaping.  It then became necessary in wards that
had no fireplaces, to make something as substitutes therefor.  Wooden
shafts or flues were made to answer this purpose.
  I at first made large wooden boxes, placing them in the centre of the
wards, and allowing them to extend down to within twelve or eighteen
inches of the floor. This was of great advantage, but as the true prin-
ciple of ventilation is to have an opening for the exit of the contami-
nated air at the feet of each occupant of a room, or  at the head of
the bed of  each patient in a hospital, it was soon observed that  these
shafts were too few and far between to make a very perfect arrange-
ment.
  The necessity for providing for the escape of the foul air from the
level of the floor in winter, so as to utilize the heat, was, after much
opposition,  finally established  and officially acknowledged by the
government officers.  Then arrangements were made for its introduc-
tion into  the government hospitals in a more perfect manner.
  I believe in no case, however, was it so fully carried out as to place
a ventilating flue between each bed, but in some they were arranged,
as shown (marked v) in the accompanying plans between every other
two beds.
  These flues were carried  together and  extended through the ridge
of the roof and capped as an Emerson ventilator; the opening into
the large flue,extending to just below the ceiling,was closed in winter
at all times, excepting  when the room was too warm.  This was for
the exhaust, but of no less importance was  the supply.
  The popular dread of ventilation arises in  a great measure  from
the supposition that good ventilation implies a strong draught of
cold air upon your back or feet or some  other unfortunately  exposed
place.   Such an unfortunate occurrence must be fully remedied in any
system of ventilation  before it  can become popular.
  As the simplest way of getting at this,  all the fresh air required
to supply the  partial vacuum created by the exhausting shafts was
brought in  around the stoves, and partially warmed before entering.
At  the first the stoves were entirely encased, and the fresh air allowed
to encircle  them  completely, but  experience  soon demonstrated the
desirableness of having a  portion of the hot stove exposed for direct
radiation, so that the  feeble and chilly ones might come near to it
and warm themselves.  There should always be a considerable amount
of direct radiation in every hospital; that from  an open fire is the
best, but that from a stove or steam-pipe is very good. 
Ventilation of  Water-closets.
175
  Arrangements were also made for the evaporation of a large amount
of water.
  As the first winter approached after the commencement of the war,
the idea seemed almost shocking to me of putting the sick and wounded
men  in such open barracks, generally without plastering, and made, as
many of them were, with rough boards and very open.
  But experience soon taught me the very great superiority of these
light and airy buildings over many of the elaborately finished, dark,
air-tight structures, such as hotels, colleges, new-fashioned asylums,
&c,  which the  government  was  compelled  to take,  for hospital
purposes.
   In fact, when completed with  the ventilation as above described,
with the abundant sunlight on both  sides, without  any obstructing
partitions and  abundantly warmed  in  winter, and with the proper
supply of moisture, they  made undoubtedly the most  comfortable and
wholesome class of buildings, as a whole, that have ever  been erected
for hospital purposes, not excepting even, many of the recent elabo-
rately finished buildings, where not unfrequently too much dependence
has been placed on the very meagre and insufficient effect produced
by attempts at  artificial ventilation, instead of relying more upon the
great natural means of ventilation—an abundance of large open
windows, open fires and good ventilating stoves.
   The ventilation of the latrines  or  water-closets of a hospital, as
well as  any other place,  is  a matter of great importance.
   In the  spring of 1863, I had put up in a hospital in Washington
a ventilating shaft for the latrine  room, similar to the one shown on
the  plans.   This was an  experiment,  but it  proved so satisfactory
that it  was subsequently ordered to be  applied in  all  the principal
hospitals.
   The difficulty in the isolated wards was, that  it  required a sepa-
rate fire in each shaft in the summer.   Where it is possible to get it
near the kitchen  or bake-oven fire, that  answers a splendid purpose;
but in the single wards it is not necessary to keep up a constant fire;
a few sticks of  wood every morning answer the purpose of keeping
the air in the shaft warmer than the surrounding  atmosphere, which,
of course, creates the proper draught.
   These shafts  were made very large—never  less than thirty  inches
square,  and sometimes three feet  by six feet.  The popular plan of
opening the water-closet  windows and allowing much of the fresh air
to enter the building that way was strenuously avoided; the windows 
 1'G                Unpleasant odor Prevented.

 in the closet were fastened shut, and then the air to supply this large
 exhaust shaft was drawn from  the  adjoining ward or room, which
 ventilated  that  ward and  prevented any unpleasant odor  from the
 closets returning into the ward.
   Wherever it was possible, a sheet iron or cast iron pipe was carried
up into the centre of this shaft from the kitchen, laundry, bakery or
any other constant fire,  and where no heat from a permanent fire or
from a steam coil could  be obtained, a small stove for the purpose was
provided. 
[From Sloan's Architectural Review, March, 1869.]
  THE  VENTILATION  AND   WARMING  OF  THE
         MUNICIPAL HALL, PITTSBURGH, PA.


  That there should be some artificial  force, or power, used  to
produce the proper movement of  the air, in any occupied  building
of considerable size, is now universally admitted.
  But  as to  the best manner of  applying  that force,  opinions
differ greatly.
  Many engineers think that there is  nothing equal to a fan  for
forcing in the fresh air, and, in addition to that, some use a fan for
drawing the foul air out.
  Others prefer to depend upon the movement caused  simply,by a
variation of temperature; and consider  that the same amount  of
heat required to run a steam-engine, to drive a fan, if applied
directly to  a well-constructed shaft, will  move a larger amount of
air, at a  much less cost, and in  a more  gentle, uniform  manner,
causing less unpleasant draughts.
  There can be no doubt of the possibility of adjusting the velocity
of the fan, and so distributing the inlets  and outlets of the moving
air, and  proportioning the sizes of such  openings, that, by skilful
management, almost any effect desired could be produced.
  But, as the traveller on the road, asking if  the direction he was
going would take him to Boston,  received for answer, " Yes ;" but
on inquiring the distance to that town, was told that " it was a little
more than twenty-three thousand miles in that direction ; but, if he
would  just turn around and go the other way, it  would be about
ten miles "—so, while there is no doubt of the possibility of moving
the air in any direction, or writh any velocity, we please, by fans and
steam-engines and skilful engineers, yet, if there  is a  shorter and
easier way of accomplishing the same object, let us turn around and
go that way.
  We should understand, in the beginning, that all artificial warm-
ing and ventilation is, we might almost say, a great nuisance.  It is
certainly much trouble to supply an abundance of fresh air, properly
warmed in  cold weather, and so distributed as to create no unpleas- 
 178 Artificicd Arrangements should conform to the Natural

 ant  draughts  in  any part of the building; and, as changing  its
 temperature materially detracts from,its freshness  and purity, it
 must necessarily be inferior to the natural condition of the external
 atmosphere.   But, until we get to migrating, as the birds  do, in
 spring and autumn, so as to keep in a warm climate, we shall have
 to continue supplying ourselves with artificial heat, no matter at
 wThat cost of  money and care;  and it is almost time for us to com-
 mence making an attempt at supplying ourselves with  partially
 pure air.  We should take the natural conditions of the atmosphere
 for our guide, as far as possible.   Man is an artificial animal in
 many respects.  He can thwart or reverse some of the minor law.i
 of his creation, but frequently pays heavy penalties therefor.
   To be sure, in all our buildings the warming of them and their
 ventilation are almost entirely artificial; but we should endeavor to
 imitate, as nearly as may be, the action of the great source of heat
 and motion—the  Sun ;  and the nearer we can imitate and  follow
 the natural movement of the air, the nearer we  will come to per-
 fection.  By reference  to the accompanying plans, it will be seen
 that all the heating, both by direct radiation  and air currents, is
 placed around the exterior walls, at and below the floors; because,
 in the first place, we want the greatest amount of  heat wHere the
 greatest amount of  cold is, so  that they will  neutralize each other,
 and produce a uniform temperature over the whole room; secondly,
 the inlets of the fresh air are on the exterior, and the outlets for the
 foul are mostly tow-ards the interior, because the Central Hall  in
 this, as in all other cases, is  the  great  natural  ventilating  shaft.
 Although it is very necessary to have other ventilating shafts, that
 can be definitely controlled, for  special  and  specific purposes, yet,
 in a large public building, with the doors opening and closing con-
 tinually, it is  impossible to prevent a great  central shaft, of that
immense height, from becoming a grand ventilator;  and, when all
 other arrangements are made in accordance with this, fact, it is very
 desirable that  it should be so.
  Now, if the  arrangements for heating were placed in the interior,
 and near the hall doors, as is usually done, then the moment those
 doors were opened, the heat would rush out there, and the cold air
would suck in at the opposite windows, sweeping across the whole
room to  the  hall, chilling every one in its  passage, and causing
 universal dissatisfaction and complaint.
  But, if  the  floors and exterior walls can  be kept to about the 
JT.W.Xfirr.Archi
                 SECTION
                   Showing
    VENTILATION & HEATING
                    OF THE
MUNICIPAL HALE, PITTSBURGH, P* 
 
Fig.  37.
               CELLAR.
MUNICIPAL HALL, PITTSBURGH, PA.
11 
182                   Ventilating  Shafts.
temperature of the body, 9S°; and if  the  excessive  cold  of  the
windows is counteracted, by steam  radiators under them, then the
transoms over the doors maybe left  alwavsopen, and even the doors
themselves could  be safely left open much  of the time, forming a
liberal and excellent ventilation.
  If, however, we should allow the  main hall  to become the venti-
lator for  the water-closets, the  boiler-room, etc., it would be  an
offence to the whole  building.  Separate ventilating  shafts must,
therefore, be provided for these ;  and it is also necessary to have a
separate arrangement  for the ventilation of  each room, in case it is
desirable to  close it entirely ; and thus disconnect it from the main
hall.
  For  this  purpose, two large shafts have been  provided by the
architect, communicating most  directly  with the water-closets, and
by direct  or lateral ducts with exits in  the  floor of every room in
the building, as well as with exits  directly over the chandeliers in
the ceilings  in the principal rooms.
  There is  another advantage to  be gained by the use of these
shafts: In spring and autumn, when the external atmosphere is too
warm  to require  sufficient additional heat to cause the necessary
motion of the air, and yet too cold to allow of the windows being
open;  then, by heating the air in these shafts, by steam-coils, if the
boilers are in use, and if  not, by an ordinary stove or  furnace that
will be placed there for that purpose, the air will be set in motion
over the whole building.
  It is just at this point that  the closest  comparison  should  be
made between the values of the fan and the heated shaft for moving
the air, because in winter, when  there is a  considerable difference
of temperature between the external air and that in the building,
all  the flues draw freely,  and it  is very easy to keep  up sufficient
circulation; and in summer, when the windows are all open, a fan
would be perfectly useless.
  The ventilating shafts, as shown on the plans  and  section, com-
mence at the foundation, four feet by seven in the clear each,  the
two giving an area of fifty-six feet.
  Their  capacity is increased thirteen  square feet each, where the
additional foul-air ducts enter, above the fourth  story, thus  giving
an  aggregate of eighty-two square feet of ventilating flue.
   Now,4we  want to know how much air these shafts will move, and
how much coal will be  required for the purpose. 
            Number Cubic Feet of Air  Discharged.        183

  Of course, in making these estimates we lay aside all other sources
of motion, such as the artificial heating, external currents, etc. and
suppose the air in the building to be perfectly stagnant.   Such con-
ditions would  scarcely occur  six  days  in a whole year, but then
those six days must be fully provided for.
  One pound of coal will heat from thirty to forty thousand cubic
feet of air 10°.  Now we find, theoretically, that a temperature of
10° in excess of surrounding atmosphere, will give, in a chimney
one  hundred feet  high, a velocity of more than eleven  feet per
second.  Suppose, then,  we allow the six feet for friction (which
would be larger than necessary in a flue of that size, made perfectly
smooth), we still have five feet per second for the velocity of the
moving current; and this, I believe, will  be generally exceeded in
practice.  Eighty square feet for size of shafts, with a velocity of
five feet per second, gives 24,600 cubic feet a minute, or 17.000,000
(omitting the fractions) in a day of  twelve hours.  This would be
an abundant ventilation for this building.
  Now, to warm these 17,000,000 cubic  feet 10° in  the shaft, for
the purpose of giving it this motion, would require only 566 pounds
of  coal, supposing  30,000  cubic feet to  be heated by one pound,
which is a small allowance.
  Let us compare this result with that of the fans in the Capitol at
Washington, probably the most perfect in construction of any in
this country, if not in the world.   According to the report of the
engineers, they burn,  in summer, for running the fans for ventila-
tion, 3,000  pounds  of coal in eight hours.  This supplies the two
engines, one of 30-horse power to drive the fan for the House of
.Representatives, and one of 16-horse power, for the fan of the com-
mittee rooms, etc.
  I have never seen the  record of any accurate experiments, giving
the  actual amount of air delivered ; and  the amount, as guessed at
by  different parties, varies greatly.  Some give it as high as 60,000
cubic feet per minute  for the large fan, and 30,000 for the smaller
one.  But the engineers say that 40,000 for the  larger  one, and
25.000 for the smaller, is quite as much  as they ever  deliver per
minute,  in  practice.  This, for the eight hours  they are  running,
gives 31,000,000 cubic feet, or a fraction over 10,000 cubic feet of
ventilation for every pound of  coal burned, instead  of  the 30,000
delivered where the heat is applied directly to the shaft.
  Now  this saving of the two-thirds of  the coal is but one of the 
 184         Heated Shafts more  Valuable than Fans.

 very small items in favor of the heated shaft, as compared with the
 fan.   The fan  requires the constant  employment of a competent
 engineer, in addition to the fireman demanded in both cases.
   We must consider, as above  stated, that there are scarcely six
 days in the whole year during which  such a stagnation occurs as
 would require the whole power  of the flue.  There is much of the
 time when the motion of  the external  current, or the difference of
 temperature within  the building and  out, would produce the re-
 quired ventilation without  any special  additional heat.  Also,
 whenever the fires are going in the boilers, the waste heat from the
 smoke-pipe would  cause  an abundant circulation.   And thus the
 shaft, under all such circumstances, would be doing its work quietly
 and efficiently, night and  day, without any trouble to or assistance
 from any body or thing.  But the fan would be quite useless with-
 out the constant attention of the engineer.
   Although it may be possible so to adjust the inlets and outlets of
 the moving air, and the velocity of the fan, as  to avoid unpleasant
 currents and not to create an undue pressure ;  yet, in practice, this
 is found to be so difficult that it is seldom accomplished.  If the
 outlets, from any cause, become  partially closed, the  power of the
 fan is such that it drives in the air until it becomes compressed, like
 the air of a diving-bell, inevitably causing headache.
   I think the gentle motion given to the air by the few degrees dif-
 ference in temperature, very much pleasanter, and not liable to any
 such abuses.
   An effect wall be produced, however, with just as much certainty,
 in proportion to  the power used.
   Taking all things into consideration, I  think  the heated shaft is
 at least ten times as valuable, for the purpose of ventilation, as the
 fan driven by  the steam-engine.
   Attempts to use the heated shaft have been frequently made bv
 persons who knew nothing about the principle of  ventilation, and,
 of course, have very commonly failed to produce the effect contem-
 plated.   But, because an  ignorant man burns his house up by the
 improper use of  fire, it is scarcely probable that we shall all discard
 the use of fire in our houses.
   There are several important errors frequently made in the appli-
cation of the heat to the shaft, and  in the general application of the
 shaft itself to  the ventilation of the building
  I think, in  the shaft or towers by which the Houses  of Parlia- 
         The Heat should be Placed at Bottom of Shaft.     185

ment are ventilated, a large proportion of the foul air is caused to
pass through the fire, at  the base of the tower.  This requires an
extravagant use of fuel.   It should  be burned in some furnace or
enclosure  of fire-brick, or other non-conducting substance, with a
slow draught, so as to secure, first, thorough combustion, after which
it should be allowed to heat the air in the shaft to a small  degree,
because while an additional temperature of 10°, in a shaft fifty feet
high, would produce  a current of eight feet per second (less the
friction), it would require  a  temperature of 200°  to produce a
motion of thirty-six feet  per second, or it would take twenty times
the coal to produce between four and five times the effect.
  To work economically, therefore, the flues should be large enough
to produce the desired results, with a very moderate velocity.
  Another fatal error, now detrimental to many of our large public
buildings, is to place the coils of steam-pipe, or other arrangements
for heating, at the top  instead of the bottom, with the expecta-
tion that the cold air will be so accommodating as to flow up there
itself to get warmed, before being turned out of doors.  Instead of
which the air from above falls in on  one side, is heated, and is thus
driven out on the other.
  I  have  noticed, in many large  public  buildings lately erected,
that attempts have been  made to draw down the foul air from the
third and fourth stories  of several detached  buildings, and  from
thence to  conduct  it, by one  underground  duct, to the engine
chimney, at a great distance.
  Such complicated and bungling arrangements will, of  course,
prove failures; because, when the wind  blows hard on one exposed
•building, it presses down the duct with great force, entirely over-
coming the draught from portions of the building less exposed;
and  the foul air, from the windward side of the house and the main
duct, is often pressed up  into the rooms on the leeward side.
  Another very common error  is to have a flue very large in some
places, but greatly throttled in others, as in the House of Refuge in
Philadelphia, where  an  immense ventilator  was put  on the roof,
equal, probably, to thirty or forty feet area; and, emptying  into
this, were four long  horizontal shafts, made of  rough boards, only
one foot square each, giving an aggregate of four square feet; but
on the top of the roof, for the public to look at, was the ventilator
aforesaid.
  I have been informed  that this was about the manner of execut- 
186       Ventilating Shaft should be near  Water-closets.

ing the ventilation (so called) in the new school-houses in Philadel-
phia, where they attempted  to use the heated flue, and kept up a
fire to  create a draught.
  The chimney was all right, what there was of  it;  but, in making
the connection wdth the chimney between the floors, there was only
the width of a single brick left out, or probably not a tenth part of
the space there should be.
  Of course all  such arrangements as these, besides  being a dis-
grace to the  profession, and a great injury to the cause of ventila-
tion, are stumbling-blocks in the way of the casual and  superficial
inquirer for the best system.
  There are  so many causes rendering one flue liable to interfere
with another, unless carried the entire distance  by a separate tube,
that it is undesirable to extend the system of flues to a very great
distance, especially in a horizontal direction;  and in  practice I
seldom find any occasion for doing so.  It is nearly always possible
to find some corner,  or space of little value, that can  be spared
for the purpose, at frequent intervals throughout the building.
  It is a very good plan  to place the ventilating shaft in the imme-
diate vicinity of the water-closets.   All the pipes for hot and cold
water may be carried up therein, as well as the  soil-pipes and, per-
haps, rain-water pipes also.
  They are thus  very convenient  for attachment and repairs, and
always kept from freezing while the building is occupied.  By ref-
erence to the accompanying plans and sections, it will be seen that
it is proposed to take some of  the flues from the floor of the first
and second stories down  to the  cellar, and let them enter  the heated
shaft at that point.  These will  draw off the  coldest air of  the
rooms, and it can, consequently,  be drawn  down  with the least
force.
  The flues from the top of the rooms, which are liable to be heated
excessively by the gas-lights, and  the flues from  the space imme-
diately under the floors—which it is also proposed  to have a little
warmer than the average temperature of the room—are all carried
directly upwards, and enter the main  shaft near the top.
  It is proposed to have a coil of steam-pipes in the horizontal air-
duct over the fourth story.
  Although this is heating the ventilating flues at the top, which
was  so strongly condemned  above, yet, in  this  instance—as it ti
placed so far from the main shaft, and  these flues are in the centre 
Fresh Air to be Screened.
187
of the building, and mostly warmer than the rooms—it is believed
that it wall be easier for the vacuum created by the heat to be sup-
plied by the air flowing up these flues, than in any other wray.  In
that case there would be no return current.
  The supply of the fresh air to this building was a matter of much
solicitude, as, from the immense amount of bituminous coal burned
in  Pittsburgh, indicated by the  dense  clouds of  smoke  belching
forth from its forests of  factory chimneys, the whole air is  filled
with soot.
  If a window is raised to let in the fresh air, in a few moments
every thing in the room is covered with particles of soot, some small
and some not small.
  It is, therefore, proposed to use a large room in the cellar, thirty-
six feet square  and twelve feet deep,  for a settling-chamber, and
allow all the air  for the whole building to enter that way, through
fine wire screens, which will  catch some of  the largest particles of
soot floating in the air.
  These screens will be so arranged that they can be swept  down
or  cleaned every morning, and probably brushed over with  oil to
assist in catching the particles of soot.
   In cold weather most of the fresh air that is required for ventila-
tion throughout  the  building  will be slightly warmed by passing
over steam-pipes in the cellar.
   It is not designed to heat this fresh air, but  merely to warm it to
50° or 55°, to prevent  its forming unpleasant cold  currents as it
enters the rooms.  The additional warmth required will be sup-
plied by direct radiation, from  the steam radiators shown  under
the windows, and the slightly augmented heat proposed to be  given
to the floor by the steam-pipes under them.
   This proposition of warming the floors so as to keep the feet
warm, and allow the head to be  surrounded by cool, fresh, invigo-
rating air for  breathing, is believed to be of much importance. ^
   It is so contrary, however, to the prevailing custom, which is to
keep the head in an atmosphere of from 70° to 80°, while the feet
are from  50° to 60°, that  it may take some time to become  accus-
tomed to it, and ascertain the most  desirable temperature to keep
the floor at, which is probably that of 10° below the temperature of
the body—say 88° or 90°—which would feel cool to the touch, and
perhaps be found most agreeable.
  It will  thus be seen that great care has been taken to study the 
lss              Excessive Draughts Avoided.

natural movements of the air in  the  building, and  to work with
these currents, and never to oppose them in any important par-
ticular.
  All excessive draughts have been carefully avoided; yet, wdrile
it may be almost impossible to discover any perceptible currents of
air in any of the rooms in passing through them, yet it will be also
almost impossible to find  any stagnation  of  the air  in any parts.
The heating surface is so distributed throughout  the edifice, with
the excess of heat to meet the excess of cold, that if  all the doors
are thrown open  over the  whole building, there will be  an even,
uniform  temperature throughout.   Or, if the doors should  be all
shut, with fire in the ventilating stacks, the constant motion  of the
air will be equally well secured in that way. 
[From Th£ Manufacturer and Builder (Hew York) for April and May, 1869.]
             VENTILATION AND WARMING.

                      CAST-IEON stoves.

  That  great American institution,  the  cast-iron  stove, is in
disgrace.  It has been, we think, unjustly and unmercifully per-
secuted.  There is a strenuous effort  being made to exonerate
ourselves from just censure, merited by our many sins of omission
and commission, by endeavoring to cast the blame upon this most
faithful servant of almost every laboring man's home.
  That great and successful  laborer  for   the  improvement of
American homes, A. J. Downing, devoted no stinted portion of the
brilliant delineations of his gifted pen to the unmeasured condem-
nation of this peculiar American institution.  Charles Dickens's
fertile brain  seems almost exhausted in gathering up  expressive
adjectives of condemnation  to hurl  at that "eternal,  accursed,
suffocating,  red-hot  demon of a stove, so  commonly found in
America."
  This Dr. Harris quotes approvingly, and thinks the better health
of the foundling  hospitals of Paris is because this  "accursed
stove " is unknown in those public institutions.
  Catherine  E. Beecher  and an  unnumbered host of other very
able writers strive not to be outdone in condemning the poor object
that they suppose to be the great source and cause of those  foul-air
diseases that seem to have  increased  so fearfully of late and are
causing such devastation  in our modern American homes.  Now,
add to all this Dr. Derby's very able  arguments, intended  to  call
attention to the great harm probably arising from the escape of
that intense poison, carbonic  oxide, from burning anthracite coal,
and the very learned discussions  and experiments  of the  French
Academy of Sciences showing that the virulent  poison pays no
attention to the simple, crude attempts  to confine  it  by cast-iron,
but passes through such obstructions at will, with almost as much
ease as a squirrel would  through a post-and-rail fence; and after
all  this, one can  scarcely perceive what  will be the result of
attempting to plead its  cause, to  advocate the general or  almost 
 190        Stoves more  Valuable than Gold Mines.

 universal use of this despised and persecuted article, the American
 stove.
  But we will do it, not in the interest of the stove manufacturers
 —for we have no friend in the business, and the stove is too much
 in disgrace to afford to pay for its advocacy in  that Avay—nor yet
 from mere compassion, as  many take  the part of any persecuted
 object, but from sincere conviction of  its intrinsic worth, because
 it is our belief  that its universal use, if used properly—not abused
 —would be of inestimable value to  the American  people.   We
 believe/they are of much more value to us than all the  gold mines
 of California and  Nevada.  The value of the shipping that  sails
 from our  ports and dots the ocean in every clime is but a  drop in
 the  bucket compared writh the value to us of the proper use* of  our
 American stoves.   Now, we will endeavor to give our  reasons for
 entertaining an opinion so singular and unpopular.
  Accepting as a truth that saying of  the great Dr. Franklin, that
 " Public health is public  wealth," and  which an  eminent hygien-
 ist of England lately said should  be inscribed in letters  of gold
 over every school-house and public building throughout the land,
 it becomes a question of the gravest importance as to how the best
 conditions of public health can be obtained.
  We must not take a casual and superficial  glance at a few  only
 of the prominent  members of society, who by their  wealth  and
 position may be able to attract more  attention from  the public
 than a whole factory full of men and women who labor from
 seven in the morning until six at  night; because these  wealthy
men, if they lose an hour, or a day, or  even  a month by sickness,
have no fear of losing their situations and the entire  support of  a
 dependent family.   But it is the men  and women  upon whose
strong muscles  the country is  dependent for all its manual labor
whose health must be looked after and  preserved—it is the health
of these that forms the great wealth of a nation.
  Now, one of  the great  fundamental conditions of our existence
is, that wre maintain a uniform temperature of our body, the stand-
 ard  of  which is commonly much above that  of  the  surrounding
atmosphere; and this must be secured at all  times, or existence
itself ceases.   Upon the manner of supplying  this artificial heat.
and the supply of fresh air which more or less  accompanies it,
depend the health, wealth, prosperity, and happiness of the nation
on one hand, and the  sickness, poverty, and wretchedness of it on 
           Open fires too Expensive for General Use.        191

the other.  In the  early settlement of a country, when wood is
very abundant, the open wood-fire is  not  only the  cheapest  and
simplest form of obtaining the required artificial heat, but it is in
many respects the  most advantageous to  health of any known
means.  But in large cities and  thickly-settled countries, wood is
too expensive for ordinary use for a large majority of the people—:
and the wealthy even neglect to  use wood-fires, from ignorance,
probably, of their real sanitary value.   Fires of coal in open grates
are the next most simple arrangement, and although not without
their inconveniences, yet they have some excellent sanitary qual-
ities ;  and it is our opinion it would add  greatly to the health  and
happiness of many  families, even  in  moderate circumstances, to
have an> open fire to sit by, should  they have to substitute an  old-
fashioned rag-carpet to cover the floor instead of a more expensive
one.
  But notwithstanding the  many advantages of the open fires of
wood  and coal, yet they are expensive, as they consume from  two
to three times as much coal to produce the same amount of heat in
a room as can be produced by a good stove.   The question  is  not
so much, Shall the laboring classes use stoves, or shall  they have
open fires ?  as it  is, Shall they have stoves, or shall they go without
artificial heat altogether ?   If Charles  Dickens  were to  visit  the
forty thousand paupers said to dwell in  one portion only of London,
lie would not, to be sure, find them crowded around that*" pecu-
liar American institution," the " infernal red-hot stove ; " but,  far
worse, he would  find them crowded together  in  some cold, damp,
chilly room, perhaps a few hovering over some smoking embers,
but the majority huddled together in a corner, covered by all  the
old rags they had left after calking all  the cracks of  the doors  and
windows, to keep out, if possible, any breath of air.
  Heat  is a great and  valuable sanitary agent, and if  it  can be
made available more cheaply by the use  of the stove than in  any
other  way, it is the duty of the  sanitarian to teach the people how
to use that, and not to spend his time in abusing it simply for  the
faults resulting from its misuse.  The want of a proper  supply of
fresh air when heating by the stove is one great  cause of this  hue
and cry against  the poor stove.   It does, of  course, allow a small
room  to  be shut up almost  air-tight,  and if  crowded with filthy
people, with a kerosene lamp  smoking  in the room, there is no
doubt whatever that a very foul and offensive atmosphere may thus 
192
The Franklin Stove.
be manufactured.   A bright,  open  fire  scarcely  allows  of this
abuse.  But it is the simplest thing in the world to remedy all this,
and  it can be done with the stove much  cheaper, and frequently
with more satisfaction,  than with  the  open  fire.    All  that  is
required is to bring  in  a  good supply of fresh air from out of
doors, and discharge it on the top of the stove.
  But  in attempting  to  do this it is quite strange how many very
intelligent persons will commit the fatal error of supposing that all
that  is necessary is to cut a hole through the floor, and the  fresh
air will flow  up around the stove itself, instead of which it will
simply flow out over the floor, being  heavier than  the air in the
room.  It must always be conducted to, and discharged on top of
the stove, and then it simply  falls down and  mingles with the
heated air arising around the stove.  This  introduction of fresh air
around  the stove  was very fully explained by Dr. Franklin, and
most  enthusiastically  advocated  by  him, and  he  introduced  it
largely during his lifetime through the world-renowned " Franklin
stove;" yet owing to the  stupidity or ignorance, or whatever we
must call it, of the people as to the value of or necessity for  fresh
air, this valuable feature of this  celebrated stove—in fact, all the
Franklin—was omitted, and the simple skeleton, without the spirit,
handed down with his name.
  We  have taken much pains  to inquire of  recent prominent
writers who have urged the use of the " Franklin stove "  if they
knew what a " Franklin stove " was ?   They are  apt to be  quite
indignant at the suspicion of such ignorance ; but on inquiring how
they propose supplying the  fresh  external air to their stove, they
want to knowr  what is  meant.  We have  found scarcely  a single
writer  thus questioned who had  the correct idea  of a Franklin
stove.  There  was a large number of these Franklin or ventilating
stoves used during the war, and when to the  liberal supply of
fresh air was  added an abundant supply  of moisture, an artificial
atmosphere was produced which for genial wrarmth, freshness, and
purity could scarcely be excelled by any artificial means of heating
now  known.   The success of this  manner of warming the hospitals
during our late war has given a great impetus to the reintroduction
of Franklin stoves.   Their introduction  into   the  hospitals and
barracks of England is urged by the surgeons and inspectors*  The
Sanitary Committee of the Paris Exposition spoke in the highest
terms of this system  of  heating  and ventilation as  adopted in the
United States. 
Different  Ways  of Heating.
193
  Several new patterns  of these stoves have been  gotten up in
Cincinnati, and introduced into the public schools, which give good
satisfaction.  A modified pattern  has been introduced into some
of the New  York  schools within a  few months, but with what
success Ave have not heard.
  Owing  to  the  necessity in schools of the children sitting very
close to the stove, most of those made for such positions are entirely
surrounded by the casing, thus forming  an air-chamber around the
whole  stove.   This greatly obstructs  that portion of the heat that
gives  the great superiority to  open fires and stoves over hot-air
furnaces.   We mean the direct radiation.  The  effects of heating
by direct radiation and by currents of circulating warmed air are
very different.  You may be sitting in front of an open fire from
which the rays of heat will be thrown out  so strong that you will
be kept comfortably warm, and at the same time there may be a
current of air surrounding you, and from which you  are breathing,
which passes  by you into the fire at a temperature many degrees
below that indicated by the thermometer.
  On the contrary, in a room heated exclusively by hot-air currents
you are surrounded by and breathing  air heated  hotter than indi-
cated by the thermometer; because the cold walls and cold windows
are constantly absorbing the heat of the solid bodies in the room by
radiation.
  When we  consider how much  more  active and  vigorous  the
system is when breathing the cold, bracing air of winter than when
breathing the warm, debilitating  air of summer, we can readily
understand how much more wholesome would be an  atmosphere in
which a large proportion of heat would be derived from the direct
radiation  of  a  hot  stove or  open fire, than where all the air was
vitiated by overheating for the purpose  of  securing the required
warmth in that way.
  The loud and universal complaints against all hot-air furnaces
have fully demonstrated the entire impossibility of producing a
comfortable and satisfactory atmosphere in a room by that means
only.   "With  the  open fire, the highly heated and vitiated air is
carried directly up  the  chimney.  Much heat is thus wasted, of
course ; but  this  may be far better than the wasting of the health
by attempting to breathe it.  In heating by the  stove, the air that
comes  in contact with the hot sides, and is thus heated and con-
sequently vitiated, is frequently retained in the room; this makes a
t 
194
Carbonic Glide.
stove-heated room more unpleasant than when warmed by the open
fire. But suppose there should be sufficient ventilation to carry out
of the room directly this warmed and vitiated air, and depend mostly
upon the radiation from the stove for heating,  that would be still
much cheaper than the open fire, and far more wholesome than the
heat from a miserable hot-air furnace.
  The radiation from the hot-air stove acts in all directions equally
—one must remember that the rays of  heat are thrown as much  to
the floor as to the ceiling ;  it is only the  currents of  warmed and
vitiated air that rush to the ceiling, -while the currents of cold, and
generally purer, air flow along the floor.   But if the pure external
air is brought  in on top of the hot stove, and  falls over it, the
radiation from  the stove is sufficient to keep up an equal tempera-
ture over the whole room ;  and if the supply of air by the stove is
sufficient to fill the room and allow for wrhat is carried off for ven-
tilation, there will be no cold air sucking in under  the door and
around the windows, which creates those cold, unpleasant draughts
so much complained of.  Now, a word about that dreadful poison,
" carbonic oxide," that passes through the  iron stove so easily.   It
is our belief that many hundreds and thousands die every year
from the escape  of  this  gas;  but practically the  amount  that
escapes  through  the solid  iron is probably  a very small fraction
compared with what escapes,  or  rather  is  expelled,  through the
open joints  of stoves and  furnaces, or from open fires, by badly
constructed  flues. Here is the  great trouble  with  most of our
heating  arrangements.  We believe that  poorly  constructed  and
entirely choked flues are the cause of more sickness and deaths in
the United  States than cholera, yellow fever, and small-pox com-
bined.   Few persons who have not made a general investigation of
this subject have  any conception of  the very large number of flues
in daily use  that are either entirely choked or totally inadequate
to carry off the  gases and smoke from the fires which they are
intended thus to relieve; hence the very frequent annoyance from
gas and  smoke daily met with.
  Let us illustrate by one  or two of the hundreds of similar cases
met with.   Speaking of ventilation  at the house of a  wealthv gen-
tleman, who had remodeled his old-fashioned country place two or
three years before, his housekeeper said she wished I would examine
her room in the third story, as'the gas was frequently so bad there
it almost  made her  sick.   I very soon noticed,  on  enterino- the 
Its Escape through Imperfect Flues.           195
room, an appearance of smoke escaping all around the base-board,
and, on removing that, found it  all black with smoke on the back.
A carpenter was at once sent for, and a portion  of the floor taken
up  near the  chimney, where there appeared to be the most dense
coating of smoke.  Worse and worse.  Here was the whole under-
side of the floor and surrounding joist blacked and almost charred.
Here we soon discovered an open flue that appeared to be discharg-
ing  its whole contents of gas and smoke simply under this floor;
and with a string and  a bit of iron  tied to the end of it wre traced
the  flue to the large stove in the hall, which had thus been dis-
charging the whole of its smoke, waste heat, and gas for two winters,
and just commencing the  third, directly under  this floor.  On in-
quiring, it appeared that on remodeling the house, instead of the
old-fashioned open fire in each room—which makes the best venti-
lator in the world—the proprietor thought they must dispense with
these great  nuisances, and have  the  whole  heated by hot-air
furnaces; and  of course, when  the  lady found that there  was  a
great flue alongside of the  closet, of  no earthly use, only just for  a
ventilating flue, it wras at once ordered to be cut away and the closet
enlarged all  that much, to her  perfect delight.  A very common
way of utilizing such useless space as ventilating flues !  And  then
the stupid furnace man, finding  a hole in the wall, stuck his stove-
pipe in, perfectly regardless, as  usual, as to where the smoke was
discharged,  provided it would " draw "—obtained his money and
left. There  had been no complaints of the draught in this case,
as there was  plenty of space for it to be discharged into the rooms
above.
   One more  illustration of the great  annoyance of carbonic acid gas
and carbonic oxide  gas passing through the  iron of the ordinary
furnaces and escaping into the room.  A few years ago we bought
a new house  in Philadelphia, which the builder was  to have com-
pleted in six weeks.   Of course, American like, we were ambitious
to  live in as large a house as we could possibly raise the money to
purchase—and that was small.   As  houses for  sale were scarce in
the neighborhood in which we desired to locate, a critical examina-
tion was waived until completed and possession given.  Afterward,
when the flues  were examined carefully for the purpose of putting
in  the heating apparatus, wmat should we discover but a lot of those
little mean  Philadelphia flues,  four by eight  inches, left without
plastering, and as rough inside as the face of  a  limestone turnpike. 
196
Everything Saturated by it.
Here was trouble.  To live in a house with such flues I knew would
be perpetual torture, a daily chronic irritation from escaping gas
and  smoke, and  a  constant complaint for want of the proper heat
and warmed air for ventilation ; but my wife and daughter, as fond
as they were  of good ventilation, were  entirely oblivious to my
pleadings as to the necessity of tearing  down the entire breastwork
and  building  up new flues. They demonstrated  very easily, that,
in the first place, we could not afford to go to the additional expense;
and, in the second place, it would completely spoil the new plaster-
ing, as we did not expect to have the walls painted at once; and
thirdly, that  the  rooms were already so small that we could not
afford the additional room to build suitable flues;  and we could not
do as they do in Kentucky, for the purpose of getting more room,
build the chimneys out of doors,  from the fact that there was  but
a brick on edge between our own and our neighbor's flue.  Many
consultations were held and contrivances suggested for doing what
never yet has  been done—making all the smoke from a good-sized
fire, and  a sufficient quantity of warmed air for a good-sized room,
go through little rough flues like these.
  One fine, clear morning, feeling a little more  courageous  than
common, I ordered the top taken off the chimney and  the whole
breastwork taken down to the cellar, not leaving one brick upon
another of the whole  flue-work, and had them built up properly.
The enjoyment of good draughts and bright fires fully compensated
for all the trouble.  I was not at  home when the fires were kindled
the second  winter;  but  my  wife's letters  were prefaced  with
" Carbonic acid—dreadful poison—carbonic oxide—the flues smoke
dreadfully," etc., etc.   It at once flashed  across  my mind that  I
must have been  so unfortunate as to have left that little pamphlet
of Dr. Derby's lying about, and my wife had got hold of it.  I an-
swered that the flues were not sufficiently warmed, but after a little
while they would certainly draw better.  This was accepted as such
sound philosophy that the building up of fresh fires, which filled the
house with smoke, and,  when coal w^as put on, with gas also, was
cheerfully persisted in.  But upon my arrival home, instead of the
pure, sweet house I was accustomed to, I noticed at once the smell
of gas and  smoke, and a very disagreeable odor  seemed  to  have
saturated everything—in fact, it smelled like other people's houses.
The family said it was not as bad  as it was at first; they were getting
used to it.  My very philosophical explanation of  the cause of the 
The Mystery Solved.
197
 smoking seemed to be somewhat questioned, as three weeks' per-
 sistent firing had not sufficed to get the chimney warmed sufficiently
 to keep it from smoking dreadfully every time the fire was kindled,
 or to prevent the gas from pouring  out when the coal was put on.
 It was so glaringly incorrect that I had to abandon it and commence
 a search for some remedy that would leave a less unpleasant odor.
 The fire was allowed to burn out in the furnace, and a diligent
 search commenced for the cause  of  offence in these new  flues.  (I
 should  have remarked  that the man who put up this furnace had
 been sent for, and, after a thorough (?) examination, pronounced it
 " all right,")  There was a stove in the third story, the pipe of which
 entered the furnace-flue.  I commenced there by withdrawing the
 stove-pipe,  and found a splendid draught.  From there I went to
 the cellar, took down the furnace-flue, and found  the smoke pre-
 ferred going out to going  in.   My wife then commenced  throwing
 pieces of coal in at the pipe-hole in the third story, while I listened
 in the second story  and  heard them rattling down with perfect
 freedom.   Listening in  the parlor, they were heard rattling along
 to a point just opposite the parlor  mantel, where I heard them stop,
 as our friend from the Green Isle would say.   More trouble ahead.
 I sank  back in  the  chair in a fit of  perfect dejection.  As I sat
 there, with the drops of perspiration rolling off my face, endeavor-
 ing to calculate how many days it would take to get the mantel-man
 out from town to take the marble mantel down, and then get the
 bricklayers to cut open the flue to remove the obstruction, and get
 the mantel reset, and to  get the  plasterers to come and patch up
 the plastering;  also, about  how  many months'  income it would
 require  to  pay for it; and, upon the  whole, wmether we would not
 have  to put  up  stoves and run the  pipes out of  the  windows, or
 somewhere  else; all at once a bright idea flashed across my mind—
 to have some burning coals thrown down from the pipe-hole in the
 third story.   I waited and w'atched some little time and felt almost
 in despair, until at last down came a coal of fire, and then a strong
 woolly smell soon  filled the cellar.  Upon looking in at the pipe-
hole I noticed  large pieces of blanketing tumbling down.   The
whole mystery was now solved.   The servant-girl, the preceding
winter, had stopped up the pipe-hole with a piece of blanket, and it
was found easier to push that into the flue than to pull it out when
they put up the stove.  I scarcely need add that the splendid draught
was  established as soon as the chimney became heated, to the great
12 
198
Advice  to Householders.
rejoicing and comfort of the family.   There was no more trouble
about " carbonic acid" or "carbonic oxide " through the solid iron.
   Now I would  just like to suggest  to  the  French Academy of
Sciences, who I understand are at present much exercised about the
gas phenomena, the propriety of  examining this  blanket question,
and give  the hot-coal experiment  a thorough trial.   I can assure
them from  my own  experience  that  the public would be utterly
astonished  at a correctly prepared  statement, showing the  large
proportion of flues that are entirely choked up with blankets, mortar,
soot, or their equivalents, and the almost universal inadequacy of
modern flues to perform the service required of them.  And until
the public good shall be served by the timely smothering to death—
which  fortunately is rapidly occurring—of the present generation
of  wilfully  ignorant  architects  and builders,* I would  advise all
persons purchasing new houses at once to tear the  chimneys  down
to the foundation and put in the improved terra cotta flues—cheaper
in the  end than  brick—before  ever attempting  to occupy them.
We know this will be a very unpopular recommendation, and but
few mechanics who have stoves or heaters to  sell will risk selling
their wares by giving any such advice, because their neighbor will
say to the owner that " his house can be perfectly  warmed and ven-
tilated  without going to any such expense, if he will only use their
apparatus."   Soothsayers and deceivers all of them.   It is  but one
continued deception and disappointment.  Such flues are like aching
teeth ; the sooner they are out the better.  With a well-constructed
flue, and consequent strong draught, with the combustion which can
be  and should be completely regulated by  the  admission of air
under the fire, controlled by a perfectly air-tight damper, and no
damper in the smoke-pipe—which it should be against the law to
use—ninety-nine hundredths of  all the practical difficulties about
the escape of gas would be  gotten rid  of.  And then, perhaps, the
wisdom of the French Academy of Sciences will be  able to suggest
some remedy for the remaining  portion, which no doubt may" still
persist in oozing through the iron castings.
  * This was written two or three years since.  There has been a great change in
the opinions of these professions since that time. 
[Prom The Manufacturer and Builder.]
                 VENTILATION—COOLING.

  It comes so natural to say ventilation and warming, that it is
quite an effort to substitute cooling; it is quite a necessary substi-
tution, however, for such weather as we have been passing through
for the few months past.  And why not pay some little attention to
the additional comfort that might be gained three  or four months
in the year, by a little attention to artificial  cooling, as well as to
devote so much to the artificial heating for the six cooler months.
One of the most easily reformed discomforts to which New Yorkers
are so universally subjected is the heat and smells from the kitchen.
In  summer, when the kitchen is  so much hotter than the rooms
above, this disagreeable feature of our basement  kitchen is  especi-
ally noticeable.  Our elegant houses soon become unendurable, par-
ticularly for our wives and daughters, wdio are obliged to flee to the
mountains or to the sea-side, to escape this disagreeable par-boiling or
premature roasting, which would have to be endured if the summer
were spent in any of our fashionable city houses.
  Why is it that men of intelligence, men of good ordinary common
sense, wTill allow their architects and their builders to spend*immense
sums  for the erection of a magnificent residence, and allow them
to put the great fire directly under it, without a single crack  for the
escape of all the surplus heat and smells excepting by the main
stairway ?  You can scarcely broil a steak or make a cup of  coffee,
without filling every room above it with the odor thereof; in fact, you
might almost say the whole house  is turned into one large cooking-
pot.  Now, it takes but a small amount of common sense, and fewer
dollars than is commonly spent  in a single visit to  the fashionable
watering-places, to remedy all this.  A well-ventilated house on the
high lands in the centre of New York City should be about as healthy,
and could be made as comfortable a  place to  spend  the whole year,
summer included, as can be found in any civilized  country  on the
face of the earth.   But some very radical though perhaps quite
simple modifications would be required in their construction.
  One would be, to either ventilate the kitchens or put them in
some other position in regard to the main building.  In Philadel-
phia, the kitchen is universally placed in a back building extending
beyond the main part of the house.   This, however, is not generally 
200             Need of a Kitchen Ventilator.

applicable to the shape of lots and style of building in New York.
There would be some decided advantages in putting the kitchen in
the attic, though it might be quite  inconvenient  in other respects.
At any rate, we should prefer to allow the credit of such a radical
change in Bridget's headquarters to be given to some of the numer-
ous bodies of energetic reformers rather than to  attempt  it during
the little remnant of our natural life.  It would  be much more
congenial to our taste, and in accordance with our experience, to
disturb the general position and character of said headquarters just
as little as possible.   But instead of using the hall-way, and, in fact,
the whole house, as the ventilator for the kitchen, we would let the
kitchen have a ventilating shaft of its own; not simply a little rough
flue, some four by eight inches probably, just enough to carry off
the steam from one tea-kettle, but a shaft not  less than three feet
square—one that would be of  some service.  It  may at first sight
be thought  a little difficult to get such a flue in  an ordinary house
directly from the kitchen out of the roof—but if  it be wanted, and
there is a determination to have it, there can be some way found of
getting it with but little trouble.
   For the purpose of illustrating this  more fully,  we  have had
engraved the plans  of the basement and first story of a house now
in process of completion on  Fortieth street, near Fifth Avenue.
 By reference to these plans, for which we are indebted to L. W.
Leeds, engineer in charge, it will be seen that  there is a large ven-
tilating  shaft, A, 3x3^ ft. area, and about seventy-four feet high,
passing directly through the roof.   When  possible, it is always best
to get the  grand shaft directly over the cooking-range, but it is
frequently  quite inconvenient to do so,  and  in such cases it is
necessary to make the best arrangements possible in some other
place.
   In this case, it is a considerable distance away; but its efficiency
is secured  by carrying  the  smoke-pipe  from  the  kitchen-range
across the cellar, and into a  well-constructed flue, which  is eight
inches by twenty-four,  and perfectly straight for seventy feet  in
height, which will  secure a splendid draught at all times. Two
good results are obtained by thus carrying the smoke-pipe  across the
room.  In  the first  place, we  get rid of  the heat from the smoke-
 flue, which generally adds several degrees of heat to the rooms
 through which it passes;  and in the second place, the  excess of
 heat escaping from the kitchen-fires secures a strong upward current 
City  Dwellings.
201
LAUNDRY
^
DUMffQ* ^ROONI.
JZDST0ftv\  ""~-~^
      '77M7ZP/\
      '     "7-^7:7

PA&RLOR
ws-
'■>r\
BASEMENT
FIRST   STORY 
202    Our Houses Healthier than the Fashionable Hotds.

through the grand ventilating shaft.  The space between two joists is
used both at top and bottom of the kitchen for exhausting the air and
excess of heat into that shaft, also a large register from the top of
the hall-way adjoining  the kitchen.  Thus there will con>taiitly be
a large volume of air drawn from the kitchen, which will frequently
be supplied  by air coming in at the open doors and windows;  but
in winter, when these are mostly closed, the air will be drawn from
the rooms above, which in their turn will  be supplied by air passing
through the Avarm-water apparatus; consequently the air will flow
into  the kitchen from the surrounding halls and  rooms, and  escape
therefrom, instead of  overflowing  the kitchen  by fresh  air, as is
usual, and allowing it to escape from them to  all parts of the house.
In the evenings, especially in summer, when the lower parts  of  the
house are shut up, this shaft will draw off an immense amount of
air, and the cooler air will  flow in at  the upper windows and thus
leave the temperature of the whole house cool.
   It is thus seen that a very little ingenuity will  convert this heat,
which is  generally so annoying, into a valuable  power for cooling
the wThole house—and then our well-furnished, well-ventilated city
houses would be as much more comfortable  and healthy  than  the
ordinary rooms found at the crcAvded and temporary houses  of  our
fashionable  watering-places, as an open  cottage  in the country is
more pleasant than our present fashionable city houses.
   Of course, in winter an important part of the  arrangement for
ventilation is to have an abundant supply of partially warmed  air
flowing into all parts of the house.  In  the case  under considera-
tion, it is warmed by an apparatus that  can  be used for  hot water
in mild weather, or for low-pressure steam in very cold  weather.
Of course, great care is taken not to have too much  warmed air in
the  house, as that is necessarily very debilitating; but every room
is well provided with direct radiation, in some of the rooms from
open fires, and in others by exposed pipes, heated by steam or  hot
water.  Several pipes  are also run along  under  the floor  by  the
windows, for the purpose of keeping the floor warm and to coun-
teract the cooling influence of the exposed windows.   Special ven-
tilators are  placed over all the gas-burners, and  wherever possible
the warmed air is brought in at the  coldest point of the room, which
is of course under the external  windows.
   The foregoing cuts are copies of  the original  plans made before
the building was erected, and the above  article was written before 
Carrying Smoke Down instead of Up.         203
 the  work was done.   It is now interesting to know the practical
 working as executed.
   In attempting to start fire in the kitchen range in the Autumn I
 noticed an unusual interest  manifested by the mechanics  about
 the building,  and on inquiring I  found a decided opinion of in-
 credulity as to the success of the attempt to carry the smoke from
 the range in the kitchen down to the bottom of the cellar and across
 to the smoke pipe, as indicated on these plans.
   I learned there had been  previous attempts to light the fire, which
 had  filled the  whole house with smoke.
   Care had been taken to explain to the proprietor that it would be
 necessary on  starting  a fresh fire  when the flues  were all cold to
 first build a fire at the bottom of the main shaft before lighting one
 iu the range;  but as he was  not present this had been neglected,
 and  of course the  newly completed flues being damp and  cold,  not
 a particle of smoke or gas would go that way.
   The heavy gases would  accumulate in  the flue below the range,
 and  there remain.
   The cOok was in a grand  state of excitement, declaring it was  en-
 tirely against nature to attempt to make the smoke go down instead
 of up ; she knew it would never work, and she could never do a
 thing with it.
   As the family expected to move in the next day, the time seemed
 short to effect so radical a change in the education of that impor-
 tant  personage ; and from my many former attempts  at such educa-
 tion, I deemed it quite prudent to acquiesce at once in the proposal
 to send for the range man  to turn  the smoke into the usual flue
 immediately over  the range, and allow it to pass up through the
 library and main rooms of the building as usual.
   But the delay of a few hours in the arrival of the range man gave
 me a good opportunity to build a fire at the bottom of  the upright
 flue,  and have a bright hot fire in the range on his arrival.  The
 draught of that flue was then magnificent, and no doubt would have
 been quite sufficient as long as there was a fire in the range every
 day.
  But it is not desirable to resort to the expedient of  carrying  a gas
 flue downwards if it can possibly be avoided.
  An excellent draught may be secured in this way most unques-
tionablv, but additional care is required in  starting the  fires when
the flues are cold; and again, any opening into the flues below the 
20-1          Care Necessary in either of these Cases.

level of the fire is liable to give  much trouble  from the leakage
of gas.
  By a little ingenuity the  smoke flue might be carried across the
kitchen ceiling, thus avoiding the foregoing objections, or by care
a double flue might be made upwards through the wdiole  house in
the usual position.
  Some additional care would be required in either of  these cases,
but the object to be  gained, that of thoroughly  ventilating the
kitchen and the avoiding of the additional heat  of the gas flue in
the best rooms of the house, is so great that it would  pay to go to a
very considerable extra trouble to accomplish it.
  The ventilation from the top of the kitchen into the large exhaust
shaft  is excellent, and the  general ventilation and heating of the
whole house is very good. 
               Equitable Life Assurance Society.           205


       EQUITABLE LIFE  ASSURANCE  SOCIETY.

  We  have prepared, and insert  herewith, plans  showing the ar-
rangement for ventilating and warming the new building of  the
Equitable Life Assurance Association.
  No class of  men seem  more keenly alive to the necessity for some
radical modifications in  our methods  of ventilation and warming
than our enterprising life assurance societies.
  It is as important to them to know that those persons whose lives
they have insured are not living in a foul, poisonous atmosphere, as
it is for fire insurance companies to know that the buildings they in-
sure are not filled with highly inflammable materials, or that the flues
are not carelessly built and defective.
  A well-ventilated  house for their customers is a source of great
profit to them.
  The committee charged  with the care of  the  erection  of  the
building under consideration was exceedingly solicitous that no pains
should be  spared in providing  the most perfect ventilation that
could be  devised.  Many plans  were submitted to them and urged
with great persistence.
  At one  time they were  quite favorably impressed with some of
the schemes for  forcing the  air through  the  building  by  steam-
driven fans, but after several months careful  investigation they de-
cided to  adopt the heated shafts  instead, and to heat to a considera-
ble extent by  direct radiation, and wherever possible  to have  the
radiators placed under the external windows, writh the fresh air supply
introduced directly over  each one.    These plans Avere carried  out.
Owing to the great  number of occupied stories, the fire-proof con-
struction, Arc, this building presented unusual  difficulties to the in-
troduction of   any  system of Aentilation.   Yet  those  difficulties
were very satisfactorily overcome, which should be attributed in a
great measure to the hearty co-operation of the architects, and the
determination of  the building committee  to allow nothing to stand
in the way of the thorough execution of  the plans Avhich they  had
decided upon.
  It must be  remembered that there  are eight occupied stories;
first, in the cellar there  are three large boilers  for heating and  for
power, two great engines for running the hoistways, and laundries,
water-closets, safe-deposit vaults, &c, &c. 
206            Equitable Life  Assurance Society.
  There are several  kitchens, and in every story are  many water
closets, and  all these in a fire-proof building, where no regard was
paid to keeping the partitions  one over the other.   It may readily
be imagined, therefore, that many singular contrivances had to be
resorted  to  for the  purpose of getting the flues for foul air across
from one part of  the building  to another.  In some cases the  foul
air is carried down two stories, and then horizontally 75  or 100 feet
to an exhaust shaft, and in nearly every case with perfect success.
   There are a feAV wTater-closets that  were introduced after the
building was quite finished, about which I Avas  not consulted, and
no adequate provision for their ventilation Avas provided. But these
scarcely  affect the general result.
   The aggregate area of  all the exhaust shafts is one hundred and
seventy-two  square  feet,  and by a careful measurement  of the
velocity  of  these by an  anemometer,  it Avas ascertained  that the
average w^as about six feet per second, which makes for these ex-
haust shafts alone a discharge of 61,000  cubic feet every minute,
or 37,000,000 for a day of ten hours.  This constant stream of im-
pure air is flowing from the building at all times, but so quietly as
to be almost unnoticed, and is really unknown  by a large part  of
the  occupants of the building;  and the heat being so equally dis-
tributed on the exterior of the rooms that there Avas very little com-
plaints  of cold  draught  anywhere in  the  building, and I believe
not one request during the Avhole of last winter to  close up any of
the regular  ventilators, either top or bottom.
   I  felt quite solicitous about the ventilation in the large business
hall, as it Avas so entirely surrounded  by other rooms and had  no
external windows; but the ventilation  of  that room is so perfect
that at no time, summer or winter, windy or still, can  you perceive
any  of that  peculiar odor of croAvded rooms.
   There is  at times a perceptible odor drawn in from the dining-
room, and kitchen adjoining, which was annexed after the building
was  nearly  completed, and  without  the proper attention  given to
its ventilation, and which has not yet been remedied.

  Note.—Since the  above was written, I was quite surprised to see some consider-
able modification in the heating arrangements in rooms that gave the best results
the two previous winters.  I  have not  been able to learn the reasons for such
changes, but it is probably to accommodate the peculiar individual preferences of
Borne of the parties concerned. 
NcwBuMing oJ
THIRD STORY.
         FIRST  STORY
Life Insurance Company 
 
Equitable Life Assurance Society.           209
             New  York, 110 Trinity Building, July 18, 1S71.
  The ventilation of a large  and complicated structure is apt to
present such difficulties of arrangement as in many cases seriously
to interfere Avith the appearance and even  Avith the structural
details of the whole Avork.  On this  account, I have always been
inclined to think it the most vexatious and unsatisfactory portion
of the duties which the architect is called upon to perform.   But
the result of Mr. Leeds' work as  engineer of  the ventilation and
warming of the Equitable Life Assurance Company's building has
been such as quite to overcome my former prejudice against venti-
lating engineers in general.
  The skill and tact displayed by him in arranging the ventilating
shafts and the various flues connecting therewith, in many cases
for rooms at a considerable distance from  such shafts, are certainly
very creditable to him, and quite beyond any expectations which I
had been able to form of their probable results.
  With the liberal distribution throughout so large a building of
the sources of contamination inseparable from its free and daily
use,  the  entire absence of  any unpleasant odors throughout has
become, to my mind—not in the outset, I must acknowledge, very
sanguine as to the probable results—the best  and most satisfactory
indication of an almost complete success.
                                  Arthur  Gilman, Architect.
                                   New York, July 15, 1871.
  Mr. Leeds' seiwices as engineer of ventilation and wrarming in
the construction of the Equitable Building were performed quite
to my satisfaction.   Much ingenuity was required to devise methods
for securing good ventilation to most of the rooms in so complicated
a building ;  but very general  success has been obtained, and  that
too Avithout interfering with the various and exacting architectural
arrangements.
                    Edavard II.  Kendall, Architect,
                                        120 BroadAvay, N. Y. 
210            Dwelling-House in the Country.
               Davelling-House  in  the Country.

  The accompanying plan represents the arrangement of the hot-
air  furnace, the heating flues, and ventilation for a  gentleman's
cottage near New York.
  As he proposed to have open grate fires in the principal rooms, it
was not thought necessary to go to the additional expense of  intro-
ducing steam or hot water.
  It Avill be noticed that all the registers for admitting Avarmed air
are placed on the sides of the room farthest from the door opening
into the hall and under the windows ; the warmed air consequently
has  to flow  across the Avhole room  before escaping into the hall.
  It is very common  to place them near the hall-door, and when
that is open the warmed air escapes directly up the stairway Avithout
warming the room perceptibly.
  It is also proposed to lay the A^estibule in tile, and allow a current
of heated air to pass under it so as to heat it moderately.
  This will give a pleasant wrarmth, and insure a good circulation
to the whole hall and stairway.   The whole  house  can  almost be
warmed by a heated floor in this Avay.
  In the  second story the heated  air is discharged from the  jamb
on the side opposite the ventilating flue, so that it shall be obliged to
make the circuit of  the whole room before escaping.
  The main ventilating shaft is back of the range, with the smoke-
flue from the range running up in the centre  of it.
  This will give sufficient heat to insure a constant  draught  at all
times, and  forms one of the simplest and cheapest  means  of ven-
tilating a dwelling-house that can be had.
  The laundry, store-closets, water-closets, kitchen, etc., are all ven-
tilated by this shaft. 
Dwelling-House in the  Country.
211
FIRST-STORY
CELLAR
PLAN OF DWELLING IN THE COUNTBY. 
 
LIST OF BUILDINGS FOR WHICH PLANS  HAVE BEEN
      GIVEN  FOR VENTILATION AND  WARMING.
  The  folloAAring is a list  of some of the  principal buildings for
which I have given the plans and specifications for the warming
and ventilation, since the close of the war.
  A large part of my business consists in giving these only, and in
most  cases I do not superintend the execution of the work, not
unfrequently never hearing from them after being paid for.
  Of course, in many cases the plans are so improved by the OAvner
or architects  as to be  beyond recognition by their designer, and
sometimes so improved as to be  thought worthy of an application
for a patent.
  Those coming under my notice, which have been executed with a
reasonable  degree  of accuracy,  have  very generally given much
satisfaction.

                            CHURCHES.
                                                 Architect.
St. Ann's Church, Brooklyn......................... Renwick & Sands.
St. John's Church, Clifton, S. I..................... Arthur Gilman.
Church corner Fif ch Avenue and Nineteenth Street___Not executed.
St. John's Church, Buffalo, N. Y.................... Arthur Gilman.
Methodist Church, Middletown.
Clinton Avenue D. R. Church, Newark.............. Thos. Roberts.
Church cor. Twentieth  Street and Sixth Avenue, N. Y.
St. John's.  Chicago, 111........................... Cass, Chapman.
Baptist Church at Troy, N. Y.
Wabash Av. Church, Chicago........................ Rose & Chapman.

                  COLLEGES AND  SCHOOL-HOUSES.
                                                 Architect.
Findlay Street Public School, Cincinnati............. Board of Education.
Public School at Orange, N. J...................... J. P. Huber.
Public School at Worcester, Mass.................... Earle & Fuller.
High School at Hartford, Conn..................... G. H. Gilbert.
Public School at Salem, Mass....................... Martin & Thayer, not ex'd.
Farnham College, New  Haven, Conn................Russell, Sturgis, Jr. & Co.
Public School at Albany, N. Y......................Woollet & Ogden.
Theological Hall, New Haven....................... R. M. Hunt, not executed.
Stevens Institute, Hoboken, N. J................... R. Upjohn. 
214
List of Ventilated  Buildings.
                          PUBLIC BUILDINGS.
                                                         Architect.
House of Representatives, Wash.
Blind Asylum, Columbus........................... Wm. Tinsley.
St. Cloud Hotel, N. Y.
Retreat for Insane, Hartford........................ Vaux, Withers & Co.
Hudson River Hospital for Insane...................Vaux, Withers & Co.
Shepard Asylum, Baltimore........................ C. Araux.
German Club House, Brooklyn...................... C. Pfeiffer.
Senate Chamber, Albany.
County Court Room, Albany.
City Hall, Pittsburgh, Pa........................... J. W. Kerr.
Club House at Boston.............................. Ware & Van Brunt.
Union League Club House, N. Y.
New Building Brooklyn Union......................Not executed.
Treasury Department, Washington.................. A. B. Mullett.
Brooklyn Orphan Asylum........................... George Hathorne.
Chicago Tribune.

                          DWELLING-HOUSES.
                                                         Architect.
J. D. Cameron, Harrisburg, Pa......................Vaux, Withers & Co.
Dr. Tracy......................................... H. H. Holly.
Henry B. Hyde, N. Y.............................. Gilman & Kendall.
Tenant House, Boston.
W. S. Weed,  Binghamton.
B. Slessinger.
Alfred Mills, Morristown............................ Harney.

                        BANKS  AND INSURANCE.
                                                       Architect.
Equitable Life Assurance Society.................... Gilman & Kendall.
Williamsburgh Savings Bank........................ Geo. B. Post.
N. W. Life Insurance Company, Milwaukee.......... Townsend Mix.
Merchants' Bank, 42 Wall Street, N. Y.
Sears' Block, Boston, Mass.........................  Cumming & Stars.
German  Savings Bank, New York..................  H. Fernbach&E. H. KendalL
Marine Insurance Company, New York.
Metropolitan Bank, New York.
American Exchange Bank, New York. 
subjoined are a few of the Letters received from prominent Sam>
                      tartans and others.
                     Office of the Superintendent of Health,
_,       _                                    Providence, August 5,1867.

    Your Lectures on Ventilation have been received.  I  am much interested in
them, and think the views given are correct.  I hope they will be widely circulated.
Too much cannot be said to the people upon the subject.
  Ventilation is all-important.  Indeed, I think that if the air could be constantly
kept in motion, the worst sources of impure air in our cities would be rendered
almost free from danger.
  In seasons of epidemic cholera, the most oppressive feature of danger is  the
stagnation which exists in the atmosphere.  There was good sense and true philoso-
phy in the old custom of burning bonfires to keep off disease.  I must close, wish-
ing you much success in your efforts to awaken the people to tho importance of this
subject.   ^
                           Truly yours,
                                         EDWIN M. SNOW, M. D.,
                                                  Superintendent of Health.
                                        Bangor, Maine, August 23,1867.
My Dear Leeds.
    Tour  pamphlet was duly received.  I have read it with much interest, and
believe it  to be worthy of extended circulation.  It is the clearest paper on the
subject I have yet read.
                        Yours, in haste,         A.  0. HAMLIN, M. D.
                           64 Madison Avenue, New York, Aug. 23, 1867.
My Dear Friend.
    I have just read your Lectures on " Ventilation," and I am very much obliged
to you for the entertainment and instruction they have given me.  You havo very
happily hit upon a stylo which is neither flippant nor dry. I am sure the lectures
will be read, and if read, they will do a great deal of good.
  I have all my life been  talking and writing in this  direction, imploring the
people to take less medicine and more puro air; and I feel truly grateful for the
help your strong shoulders have given me in what has thus far proved to be a labor
pf Hercules. 
21C
  Your particular method of ventilating buildings I had many opportunities of
proving while I was Medical Inspector U. S. A., and I assure you that no plan was
ever more simple and inexpensive—none could have been more effective.  Indeed, I
may say that I never knew it to fail.
  To you, therefore, I fully believe  the country is indebted for the lives of many
thousands of men.
            With sentiments of esteem,
                           I remain yours truly,
                                  FRANK H. HAMILTON, M. D,
              Prof. Principles of Surgery, Military Surgery, Hygiene, &c,
                                    Bellcvue Hospital Medical College, N. Y.
Author of Work on Fractures and Dislocations, Treatise on Military Surgery, &c.

  L. W.  Leeds, Esq.

                       Office of the Metropolitan Board of Health,
                                     No. 301 Mott Street,
                                           New York, August 26th,  1867.
Friend Leeds.
    Your Lectures on Ventilation have given me much pleasure, and have renewed
my confidence in the utility of  popular instruction upon the subject.  I heartily
thank you for the thoughtful care with which you have set forth all the essential
principles of ventilation, in language so free from technical words, and so full of
plain and homely illustration, that even an uneducated reader can fully understand
all you have written.  The good Dr. D. Boswell Reid,  Dr. Wyman and myself
had each attempted to use such a style of explanation and instruction; but you have
far excelled us all.
  The first want of every living being is fresh air, and unless the human lungs arc
supplied with such air constantly at the rate of from ten to thirty cubic feet  every
minute, by night as well as by day, perfect health and vigor cannot be preserved.
Then, too, there are exhaled from the surface of the body and from the lungs, such
quantities of waste organic  matter, which tend to immediate putridity,  that it,
together with the carbonic acid, would keep the human body immersed in a deadly
vapor of these exhalations, were not fresh air supplied.  The illustrations by which
you have made these truths easily understood, are admirably given in your lectures,
and the method, by which you  would best insure success in removing the foul  and
supplying the pure  fresh air in every place where persons live or sleep, are, as I
believe, from my own careful studies of this subject, most correct and trustworthy.
Indeed, I am able to say that, in my examinations of the vast  number of hospitals
and buildings which you ventilated during the late war, under authority from the
intelligent and humane Quartermaster-General  of the army, the  proof of  entire
success in your work was everywhere witnessed.  Simplicity, invariable certainty
and a liberal sufficiency characterizes these admirable methods of yours.
  I wish every family in the land had a copy of these lectures.
                          Sincerely yours,

                                           ELISHA HARRIS, M. D.,
                      Corresponding Secretary Metropolitan Board of Health.
  To Lewis W. Leeds, Esq. 
217
                                 Vaux, Withers & Co., Architects,
                         No. 110 Broadway, New York, August 27th, 1867.
Dear Mr. Leeds.
    I am glad to receive your Lectures in printed form, and trust that  they maj
be widely read throughout the community.
  Having been in the habit for several years past, of consulting with you profes.
sionally in regard to the arrangements to be made for heating and ventilation in
plans for public and private buildings, I  take this opportunity to acknowledge the
value of the aid thus given;  and as  I  feel assured, from a lengthened persona
experience, that your thorough knowledge of the subject, both theoretically and
practically, is calculated to  render your assistance particularly valuable  in  the
adjustment of complex and intricate plans, I  trust that one result of the circula-
tion of your interesting pamphlet may be to introduce you more widely to members
of the architectural profession.
                      I remain, Dear Mr. Leeds,
                                      Yours faithfully,
                                                     CALVERT VAUX.
   Lewis W. Leeds,
       Heating and Ventilating Engineer.
                               110 Broadway, New York, Aug. 30th, 1867.
    Mr. Lewis W. Leeds wa9 employed early in the war of the rebellion by the
Sanitary Commission, as an agent to urge the necessity to the health and strength
of the army, of the thorough ventilation of tents and quarters, and to devise and
suggest to the proper officers the adoption of the best means for this purpose.
  At a later period of the war, at the suggestion of the Commission, the Quarter-
master's Department engaged his services, and gave him large discretionary powers
for the ventilation of hospitals.  He was thus employed during all of the war, with
great advantage, and the improvements which he brought about were unquestion-
ably the means of saving thousands of  lives.       *        *       *
  Mr. Leeds has a special talent for making  improvements  in houses of ordinary
construction, by means which may be  readily adopted, and with materials which
may be anywhere procured without difficulty or great expense.
  Mr. Leeds' course of lectures on Ventilation is calculated to supply instructions
of great  practical utility.  An invaluable addition to tho health, happiness and
wealth of the nation would result, if they could be delivered before every school
in the countrv.
                                           FRED. LAW OLMSTED,
                         First General Secretary of the Sanitary Commission
                                       Treasury Department,
                        Office of the Supervising Architect, Sept. 11th, 1867.
My Dear Friend.
    Your valuable Lectures on Ventilation" have  been received,  and have been
read with much pleasure, more especially as you are about the only person I have
ever met, who, after making the ventilation and heating of buildings a specialty,
has condescended to follow the laws of nature, and provide the means of adapting
                13 
21S
them to our artificial modes of life.  Your lectures show a thorough study and
knowledge of the principles involved, which are, like all natural principles, verj
simple if once understood.  I have also to take this means of acknowledging the
valuable aid that I have  received from you on many occasions, and to express a
hope that you will not despair, but relying on  the adage that " truth is mighty"
&c, go on with your exposures of the absurdities of the complicated and costly
humbugs that are so fashionable at present, and trust you will succeed not only  in
ydur missionary labors, but find them pecuniarily profitable.
                        Very respectfully,
                                                A. B. MULLETT,
                                                   Supervising Architect
    Lewis W. Leeds,  Esq.,
Engineer Ventilation and Heating,
                Germantown, Penn'a. 
IN  DEX.
Advice to purchasers of new houses, 198.
Agitation of the air the great desideratum, 52.
Air.
    a real substance, 28.
    amount breathed in twenty-four hours, 73.
    amount breathed per minute, 73.
    amount  breathed subject to  extreme  varia-
      tion, 74.
    as pure at night as in the day, 22.
    can never be at rest, 33.
    change in its electric or ozonic condition, 34.
    expansion of, by heat, 55.
    formed of groups or families, 104.
    heated only by immediate contact, 33.
    its composition, 90.
    its individual particles widely separated,  102.
    its supply much more important than food, 74.
    moist not injurious, 18.
    non-absorbent of radiant heat, 32.
    not  influenced in purity or foulness  by tem-
      perature,  35.
    not warmed by the rays of heat, 30.
    pure, good for cholera, 21.
    tables giving analysis of, 14.
    thirty pounds breathed daily, 74.
American manner of  killing yourself by  careless
      eating, 98.
American stoves heated white hot instead of only
      red, 168.
    no fresh-air boxes to, 168.
Amputated Km& cured by pure air, 76.
Analysis of air not taught by medical colleges, 93.
Artificial ventilation  and heating always  inferior
      to natural, 178.
Asylum for Blind, Columbus, Ohio, 141.
    air drawn down as little as possible, 144.
    detail plans, 143.
    horizontal pipes avoided, 144.
    ventilated by heated shaft, 142.
    warmed  half by  direct radiation; half-warm
    air currents, 144.
Atmospheric pressure in high winds equals  many
      tons, 142.
Atmosphere, pressure of, upon one man, 28.
Author's experience with hot air, 128.

                       B.
Back; always keep warmer than face, 106.
Bad smell on opening car-door, 48.
Bed-rooms.
    difference in air of, if  confined, greater than
      between city and country, 18.
    foul air in, 10.
    how best ventilated, 43.
    open fire good for, 21.
    small one,  well  ventilated, better than  large
      one not ventilated, 24.
Blankets should be used freely to  allow of sleeping
      with open windows, 85.
Blood.
    amount of, represented by diagram, 74.
    bad effects of impure air upon, 72.
    best way to purify, 75.
    carries the poison of foul air to every portion of
      the body, 49.
    pulsations average 72 per minute, 74.
    the color changed by oxygen inhaled, 72.
    the regulations of its circulation gives us great
      control over the body, 74.
    thoroughly poisoned in cars before your break-
      fast is digested, 49.
Board fence heated by sun's rays, 104.
Board of Health of England  gives 198,000 deaths
      annually as preventable, 84.
Board of Health of New York say ventilation is
      the very first sanitary want, 171.
Board of Health of Philadelphia advice  about ven-
      tilation, afraid of night air, 20.
Boarding-school at Westtown, 166.
    flues of old fire-places utilized, 156.
Breath.
    a deadly poison,  23.
    experiments showing where  this  poison accu-
      mulates, 24.
    extinguishes a candle, 23.
    it should be removed  immediately from the
      room, 94.
    number of seconds required to fill a jar,  93.
    the popular idea that it rises erroneous, 24.
    practice based upon this theory incorrect, 24.
    we know too little of its component  parts, 93.
Breathing.
    air  should be cold for, and body  heated by
      radiation, 106.
    effect of temperature thereon, 93.
    greatly increased by exercise, 74.
    pure air  more than ten times the importance of
      eating, 77.
Breathing tubes for discharge air suggested, 95. 
220                                       INDEX.
Bridgets headquarters, great risk in disturbing,
      200.

                       C.
Capitol at Washington, 104.
    absence of direct radiation in, 115.
    attempt to produce artificial heat, light, and
      mixed air not equal to nature, 115.
    diversity of opinion regarding ventilation in,
      114.
Carbonic acid.
    absorbed by growing plants, 16.
    escape of,  from imperfect flues, 196.
    experiments showing excess of, at floor; chil-
      dren near floor killed by it, 25.
    formed by burning candles,  absorbed by lime-
      water, 91.
    greatest amount found in Manchester, 15.
    in dormitories, asylums, schools, &c, 17.
    in houses,  16.
    in lecture-rooms, 17.
    more exhaled in breathing cold than warm air,
      93.
    more formed  in a bedroom in seven minutes
      than found in Manchester, 16.
    or ashes result of combustion of oxygen, 71.
    proportion in exhaled breath, 93.
    the breath contains 100 times the natural quan-
      tity, 94.
Carbonic oxide, escaping from choked flues, worse
      than cholera and yellow fever, 194.
Carbonic oxide gas, author's experience in regard
      to, 195.
Carpenter's Physiology, extract from,  on respi-
      ration, 83.
Cars, bad ventilation  in, 48.
Certificates of eminent architects, 134.
Children poisoned to death, 112.
Chilling.
    of back deranges  whole system, 107.
    or overheating much to be avoided, 51.
Cholera.
    a foul air disea e,  21.
    and malignant fevers prevented by good ven-
      tilation, 84.
    averted  by pure air, 21.
    on Blackwell's Island.  Dr.  Hamilton's pre-
      scriptions for, 22.
Churches.
    cold  air blows down  outside flues, instead of
      foul air going out, 56.
    examination of one in neighborhood, 57.
    general  practice of warming just before using
      very incorrect, 148.
    going to sleep for want of ventilation, 57.
    no ventilation seen on roof of, 146.
    St. Ann's, Brooklyn, heated by low pressure
      steam arranged under the window,  151.
    too much draught, 57.
    an illustration of  modern, 145.
    architects not always to blame, 147.
    copied after those made centuries ago, 146.
    fires should be started earlier in,  155.
    handsome frescoed ventilation on ceiling, 58.
    the fresh-air chamber sometimes used as a dead
      house, 58.
    used as hospitals, Washington, no ventilation,
      58.
Clouds, visible moisture, shield from sun's rays, 104.
Colds.
    frequently  caused by the vaporizations of mois-
      ture pf the body, 95.
    how taken  on leaving a crowded room, 97.
Cold air gives twice the capacity for work, 106.
Cold draughts in St. Ann's Church on starting the
      heater, 155.
Conducted heat, 105.
Consumption.
    a certain indication of filthy habite, 168.
    a foul air disease, 167.
    caused  by  the choking of  the air-cells with
      ashes, for want of pure air, 72.
    cured by the air of a  cow-stable, 17.
    entirely preventable by breathing pure air, 14.
    patients afflicted with, often afraid  of pure air,
      76.
Convected heat, curse of the American people, 105.
Cooling, power of kitchen fire used for, in summer,
      205.
Cooling off, suggestions in regard to danger of, 96.
Cooper Institute, want of ventilation in, 50.
Cottages for industrial classes, Philadelphia, 164.
    closed perfectly air-tight, if  possible, 168.
    great reform easily inaugurated in,  168.

                      D.
Dampers in fresh-air boxes, etc., kill more persons
    than fire-arms, 66.
Diffusion of gases, experiment showing, 99.
Direct radiation,  heating  by, in editorial rooms, 44.
Doctor Franklin.
         letter to Dr. Ingenhaus,  18.
         opinion of taking cold, 19.
   "   Hamilton cures cholera by pure air, 22.
   "   Harris's report of mortality in New York, 85.
   "   Reid's theories of  ventilation  seldom fully
            executed, 39.
         their partial execution has set a  bad ex-
            ample, 39.
Double-roomed hospitals considered scarcely ad-
    missible, 139.
Draught.
    caused by open fires,  34.
    dreadful people will not bear them, 61.
    from windows prevented, 110.
    of fresh air should fall on  the  head, 123.
    too much of,  in church, 57.
Dwelling-house in the country, ventilation of, 209.
                       E.
Editorial rooms  generally heated by steam pipes
      without ventilation, 44. 
INDEX.
221
Education.
    needed amongst the laboring classes to teach
      them the value of good health. 82.
    needed to provide sufficient ventilation at all
      times without draught, 51.
Epidemics, their fatality in precise proportion to
      amount of impure air respired, 84.
Equitable Life Assurance Society's Building, 205.
    heated shafts finally decided upon, 205.
    various plans  submitted for the  ventilation
      of, 205.
Exercise.
    a wonderful provision of nature for keeping off
      disease, but too often disregarded, 74.
    necessity for, in school children, 75.
Expansion.
    of air caused by heat, 55.
    of air, loss of power by, 56.
Experiments.
    Figs. No. 1 and 2, ventilation of bedrooms, 21.
             3, candle extinguished by immersing
               in breath, 23.
             4, showing exhaled breath falls, 24.
             5, glass house with candles, 25.
             6,   "    "  without a floor, 27.
            7, with long tin tube showing radi-
               ation of heat, 29.
             colored  lithographs  showing  circu-
               lation of air, 37, 44, 45.
             8 to 13, with flues, 53, 54, 55.
             14, showing expansion of air by heat,
                   55.
                with glass house called church, 56.
                with glass house showing currents
                   down one  chimney to  supply
                   the fire in another, 61.
             15, showing value of ventilating shaft
                   around kitchen chimney, 64.
             17, amount of air breathed, 73.
             18, amount of blood  circulated, 74.
             19, with candle to show consumption
                   of oxygen,  91.
                breathing through lime water, 92.
             20, showing diffusion of gases, 99.
                showing radiation  of  light  and
                  heat, 103.
External  atmosphere.
    Dr. Smith's analysis  of, in Manchester, 15.
    general purity of,  even in large cities, 15.
                       F.
Fans,
    general admiration of, by engineers, 177.
    in marine hospital, Philadelphia, seldom used,
      139.
    pressure  of, may equal external pressure, caus-
      ing stagnation, 144.
    value of, for ventilation compared with heated
      shaft, 182,183.
    in Capitol, nuisances, 124.
    not needed at U.  S. Treasury,  137.
    require constant attention of engineer, 184.
Feet kept warmer than head, 98, 106.
Fire boards should be used for kindling wood, 26.
Fireplaces.
    in first story supplied with air through the ven
      tilator on the roof, 61.
    from second story fireplace, 62.
    experiment showing  how  they remove  car
      bonic acid, 26.
    should never be closed, summer or winter, 26.
Flies.
    experiment with, 77.
    those in pure air die sooner than those in foul,78.
Floors and walls should be warmed, 111.
Floors warmed in Municipal Hall, Pittsburgh, 187.
Flues.
    are simply passages, 53.
    cannot create draughts, 53.
    experiments with, 53.
    for ventilation, called great humbugs, 61.
    for ventilation  capped air-tight in New York
      schools, 59.
    in outside wall, not good, 56.
    of little account in summer, 52.
Fire-room of  steamships,  good illustration of di-
      rect radiation, 123.
Food.
    eat twice in 24 hours, 98.
    Bit quiet in hot room after eating, 98.
Foul air.
    affects the blood injuriously, 72.
    carbonic acid test of, 15.
    causes cholera, 21.
    cause of 40 per cent, of deaths, 13.
         "  nearly 50 per cent, in New York, 13.
    deaths caused thereby not specified in doctor's
      certificate, 25.
    disarranges the whole system, 72.
    enormous expense caused by, 13.
    exhaustion of oxygen cause of, 15.
    experiments showing excess at floor, 25.
    experiments showing that from burning gas,
      or lamps, first rises to ceiling, 26.
    from untrapped sewers, 62.
    in bedrooms, 16.
    in cars, 48.
    in centre  of a crowd or  on steamboat in hot
      weather, 151.
    in Philadelphia schools, 59.
    killed more in  one year than the whole war,
      113.
    killed more than by enemy's bullets, 171.
    killed 13 young ladies at Maplewood Institute,
      63.
    kills more than small-pox or cholera, 51.
    number of days lost by sickness from effects of,
      13.
    number of deaths from, in Philadelphia, 13.
    on the Ohio and Mississippi,  16.
    poison of, met with everywhere, 51.
    probably killed the Surgeon-General's patient,
      76. 
222
INDEX.
     sometimes stupefies and thus  prolongs  exist-
       ence, 79.
     600 inhalations of, in half an hour, 48.
     supplied to church from filthy cellar and sewer
       from adjoining grave yard, 58.
     taken under the floor, 111.
     the position  for its escape determined by the
       relative temperature of the entering air, 43.
     very plenty in Philadelphia schools, 161.
 Franklin stoves.
     Franklin's explanation of, 192.
     used in hospitals, 192.
     used in public schools, 192.
 Friends' Meeting-house, Germantown, attempts at
       ventilation not satisfactory, 147.
 French Academy of Science, suggestions to, 198.
 Frescoed  ventilator on ceilings of  church, Wash-
       ington, 58.
 Fresh air.
   .  chambers of furnaces should not be rubbish
       receptacles, 134.
     duct  filled with sewer water, U. S. Treasury,
       130.
     for church taken from filthy  cellar  through
       which ran the  sewer from  an adjoining
       grave yard 1 57.
     good for an amputated limb, 76.
     must be supplied or you will surely die, 61.
     must have all the time, 64.
     necessary for hospitals, 138.
     should strike you in the face, 64.
 Furnace  heat, as dry as the  air of Sahara, and
       more impure, 33.
 Furnace-heated houses.—Cold feet,  hot heads, un-
       scientific, 106.

                      G.
 Gas.
     smothered to death by escape of, from  stove,
      62.
     suffocating smell  of, from cooking-stove at
      night, 62.
 Gas  and smoke, escape of, in an altered building
      described, 194.
 Gas  burner consumes oxygen  equal to five per-
      sons, 92.
 Good way of detecting blankets in smoke flues, 197.
 Government hospitals.
    cold draughts avoided in, 174.
    evaporation of moisture, 175.
    plan of, 172.
    substitutes for open fireplaces in, 174. •
    ventilating stoves in, 174.
 Grand prize, Paris exhibition, 171.

                      H.
Health, its pecuniary value not well understood.
Heat.
   a valuable sanitary agent, 101.
   enervating, 56.
   its effect upon the movement of air,  28.
 Heat.
     radiant or golden, conducted or silver, convect
       ed or copper, 102.
     the key to good ventilation, 101.
     490° doubles the volume of air, 55.
 Heated floors in country dwellings, 212.
 Heating.
     by radiation, 102.
     combination of direct radiation and circulating
       warmed air very good, 137.
 Heated shaft.
     amount of coal required to produce  currents
       in, 183.
     area of, in square feet, at Equitable, 172.
     attempts to draw air down, and from many de-
       tached buildings must prove failures, 185.
     compared with fans at Capitol, 183.
     in asylum for blind, Columbus, Ohio, well  dis
       tributed, 142.
     more simple  than fan, 177.
     size of, in Municipal Hall, Pittsburgh, 182.
     the  heat should be applied at bottom, 184.
     works constantly without attention, 184.
 Hickory fires, advantages of, 127.
 Hot air.
     author's change of views regarding, 128.
     furnace in centre of building and ventilating
       flue in outside wall, very bad, 148.
 Hotels smell bad, 134.
 Hot-air furnaces.
     how to manage them, 65.
     loud and universal complaint against, 193.
 Hot-water heating pipes at U. S. Treasury, 137
 Hot-water furnace.—Very good, but also requires
       additional  moisture, 65.
 Houses of Parliament, method of  heating and ven-
      tilating, 39.
 House of Representatives.—Sick soldiers preferred
      being out of doors, 119.
 Hydrogen does not absorb radiant heat, 32.
                       I.
 Infantile Mortality.
    delicate sanitary test, 14.
    excessive, 112.
 Inflammation caused by too sudden cooling, 96.
Inhalations, 600 of foul air in one half honr, 48.
Impure air, one breath of, weakens us, 48.

                       J.
Journalists would help by their good advice, 87.
Juvenile Asylum, well sunned and aired, 158.
Kitchen in basement causes heat and smell through
      whole house, 201.
 Kitchen and bakery ventilated by heated shaft,
      in asylum for blind, Ohio, 145.
Kitchen fire.
    a power for ventilating the whole house, 201.
    used for cooling in summer, 202.
                      L.
Lamp.
    a beautiful emblem of human life, 97. 
INDEX.
223
 Lamp.
     won't burn without ventilation, 97.
 Latrines, ventilation of, in Government hospitals,
       175.
 Ledger Building, Philadelphia, 137.
     no ventilation in, 137.
     supply of pure air in, forgotten, 137.
     ventilation is only by windows, 138.
     waste heat might be used for ventilating, 138.
 Letters from prominent sanitarians, 215.
 List of buildings for which plans were  given for
       their ventilation and warming, 213.
 Lungs.
     air-passages to, very sensitive to rapid cooling,
       96.
     if choked for want of pure air, causes consump-
       tion, 72.
     number of cells in, estimated at 600 millions, 71.
     surface estimated at 600 to 1,500 square feet, 71.
     their action represented, 71.

                       M.
 Manufacturing districts generally unhealthy, 81.
 Maplewood  Institute.
     defective drainage, 63.
     Drs.  Palmer, Ford, and Earle's report, 63.
     excessive fevers, 63.
     Bixty-six young ladies made sick, thirteen died,
       63.
     ventilation defective, 63.
 Marine Hospital, Philadelphia.
     intended to be ventilated by fan; seldom used,
       however, 139.
     no direct radiation, 140.
 Medical Colleges do not teach the analysis  of air,
       93.
 Miasma from overflowed lands, 16.
 Moist air not injurious, 18.
 Moisture.
     additional amount required in hot-air furnaces,
      65.
     an absorbent of radiant heat, 32.
     evaporation of, in Government hospitals, 175.
     forty pounds every  minute  required in the
       Senate Chamber, 66.
     generally neglected in all furnaces, 60.
     governor or regulator of heat, 33.
     its vaporization cools the body, 95.
     table giving amount required to saturate air at
      different temperatures, 61.
     the effects upon the earth of its removal for a
      single night, 33.
    the want of, causes the air-passages  to become
      parched and husky, producing irritation and
      fevers, 50.
    want of,  in furnace-heated houses, 33.
    want of,  in Public Schools, 60.
Mortality.
    greater in new-fashioned asylums and hospitals
      than where heated by open fires, 139.
    rapid increase of, when breathing warm air, 128.
 Motion the great desideratum in summer, 52.
 Municipal Hall, Pittsburgh.
     air in, warmed only to 55°, 187.
     comparative value of fan and heated shaft, 182.
     floor and exterior walls warmed in, 178.
     plan of heating, both by radiation and air cur-
       rents in outside wall, 178.
     separate  ventilating shafts must be  provided
       for water closets; 182.
     the central  hall the great natural  ventilating
       shaft, 178.
     the supply of fresh air to be screened, 187.

                       N.
 Nashville Jail, want of ventilation in, 78.
 National health  National wealth, 81.
 Natural movement of air should  be considered  in
       planning arrangements for ventilation, 142.
 Nerves concentrated near the spine, 106.
 New York city houses, plan of, 200.
 New  Yorkers universally subjected to heat and
       smells from basement kitchen, 201.
 New York  City house.
     if well ventilated, should be healthy, 201.
     when not ventilated, compared to one immense
       cooking pot, 201.
 New York.
     Dr. Harris's report of mortality in, 85.
     has many sleeping-rooms without air and sun
      light, 82.
     school houses with sham ventilation, 59.
 Night air.
     as pure as day air, 22.
     dread of, by Philadelphia Board of Health, 20.
     Dr. Franklin's opinion of, 18.
    good for cholera, 21.
    unfortunate predjudice against, IS.
 Nitrogen.
    a dilutant, 90.
    does not absorb radiant heat, 32.
    its supposed use, 74.
    resulting from a burning candle, 92.
    the proportion in the air, 74.

                       0.
 Open fires.
    disadvantages of, 108.
    exert double influence,  105.
    give the purest heat, 108.
    good in bedroom, 21.
    goose or round of  beef roasted by, while sur-
      rounded by cold  air, 34.
    inconvenience of cold draughts caused by, 34.
    radiate heat like the sun, 33.
    better to use even if rag carpets had to be sub-
      stituted for more costly ones, 191.
    frightful results of closing, 70.
    healthiest of all artificial heating—should be
      in every sitting room, 34.
Open fireplaces.
    common in Paris, 168.
    substitutes for, in Government hospitals, 174. 
221
INDEX.
Open wood-fires.
    afford the best of ventilation, 70.
    the real chimney  corner the  family sitting-
      room, 70.
Our own breath is our greatest enemy, 17.
Overflowed land unhealthy, best system of ventila-
      tion as applicable thereto, 16.
Oxygen.
    all consumed by burning candles, 91.
    amount breathed in twenty-four hours, 73.
    changes the color of the blood, 72.
    does not absorb radiant heat, 32.
    the combustion  of, leaves ashes, or carbonic
      acid, 71.
    the busybody in air, 90.
Ozone, change of, in furnace-heated houses, 34.

                       P.
Patent medicines.
    compared to pouring kerosene on the fire, 75.
    great profit realized from  sale of, 76.
Pecuniary value of health, 80.
    value of an intelligent man, say $5,000, 80.
Perfumes,  their  wonderful power of  absorbing
      radiant heat, 32.
Perspiration.
    cooling off caused by vaporization, 95.
    experiments showing average loss of, to be three
      pounds per man in fifty minutes, 96.
Philadelphia.
    average length of life in, 13.
    great diminution in number of deaths in,  68.
    most favorably situated  for introducing im-
      provements in ventilation, 82.
    physicians in, very conservative men, 83.
    public schools, 159.
    sturgeons' objections to ventilation in Govern-
      ment hospitals, 83.
    six thousand lives might be saved in, by good
      ventilation, 86.
    three-quarters of a  million dollars saved, 68.
Philadelphia cottages,  sanitary  arrangement  of,
      very good, 164.
Philadelphia Board of Health.
    recommendation to build fire every damp day
      excellent, 20.
    want to smother us to death, 20.
Physicians.
    advice of, better than quack medicines, 86.
    in Philadelphia are well informed, 83.
    still neglect to supply their patients with suffi-
      cient fresh air, 76.
    they recommend ventilation more than medi-
      cine, 85.
    Lhey say one-half of the  deaths are preventa-
      ble,  85.
Physiological effect  of  breathing  pure or impure
      air,  70.
Plants.
    absorb carbonic acid, 16.
    good in a living room, 17.
Poisoning by strychnine causes great excitement
      but poisoning by foul air  goes unnoticed
      even by doctors and medical colleges, 113.
Pressure of atmosphere diminishes in rising from
      the earth, 56.
Preventable diseases.
    cost London $20,000,000 annually, 14.
    cost Massachusetts $60,000,000, 14.
    cost New York much over $5,000,000, 14.
    cost United Kingdom $250,000,000, 14.
Public Schools, Philadelphia, 159.
    examination  of  evaporating  pan filled—but
      with half-charred brooms and water-buckets
      fallen to pieces, 60.
    not ventilated in Philadelphia, 69.
    sham ventilation in New York schools, 59.
Pure air.
    as well hope to  get through  doctoring all at
      once as to get through the troublesome busi-
      ness of ventilating, 51.
    constant care required to supply, 51.
    cures scratched fingers better than salves and
      plasters, 94.
    its supply fortunately not controlled  by a pat-
      ented monopoly, 72.
    not breathed half the time, 68.
    ray proof, 103.
    the physiological effect of breathing, 70.
    we cannot see it, 90.
    without food kills sooner than foul air, 77.
    twenty-five cubic feet per minute required for
      good ventilation, 94.

                       Q
Quack doctors, 88.

                       R.
Radiation
    author's change of views regarding, 128.
    its abuse, 108.
    manner of heating by, 102.
    of animal heat to a cold window, 109.
Radiant heat.
    absorbed by compound gas, 32.
    absorbed by moisture, 32.
    absorbed by perfumes, 32.
    candle lighted by, from hot ball, 30.
    experiments illustrating effects of, 29.
    its advantages difficult to comprehend, 128.
    not absorbed by the gases oxygen, hydrogen,
      or nitrogen when pure, 32.
    Prof. Tyndall's experiment with, S2.
    reflected  by bright surfaces, 31.
    requires different systems of ventilation. 43.
    rock salt a non-absorbent of, 31, 102.
    thrown in every direction equally, 31.
Reflection of radiant heat, 31.
Ridge ventilation as first applied in St. Louis,  172.

                       S.
Scavengers more healthy than confined operatives,
       17. 
INDEX.
225
School, every child should walk one mile going to,
      75.
School Commissioners disregard ventilation, 161.
School-house with sunshine and air om four sides
    of each class-room, 161.
Scratched finger cured by pure air quicker than by
      salves and plasters, 77.
Seioer gas mingling with fresh air, TJ. S. Treasury,
      130.
Sewers and cesspools.
    air from, drawn in by kitchen fire, 62.
    air from, may counteract the influence of  the
      most healthy situations in the world, 63.
    foul  air from, at Maplewood Institute, made
      sixty-six young ladies sick, 63.
Simple way of making buildings more comfortable
      by previously heating to 90°, 155.
Sitting-room should  always have an open fire, 34.
Skin, 2,800 perspiration tubes in every square inch
      of, 96.
Sleeping with open windows.
    Dr. Franklin's opinion of, 18.
    gives sound, refreshing sleep, 48.
    the author's experience, 21.
Smokeflue.
    choked by a blanket, 197.
    if carried down requires much care, 203.
Soil pipes should be carried up in ventilating shaft,
      186.
Spinal diseases  caused by sitting with the back
      towards a cold window, 110.
Stagnant cool air more oppressive than warmer
    air in motion, 52.
St. Ann's Church well ventilated and warmed, 155.
Steam.
    distribution of heating surface, 65.
    pipes for distributing, should be laid in all  the
      streets the same as for water and gas, 65.
Steam heating, views changed in regard to, 66.
Stoves.
    cast iron, 189.
    Franklin's explanation of, 40.
    frequent lack of ventilation in  stove-heated
      rooms, 34.
    gas escaping from, to supply draught of open
      fires, 62.
    heat both by radiation and contact, 34.
    London paupers suffer for want of, 191.
    proper way to use, 35.
    Bhould always have fresh-air supply, 35.
    the proper use of, more valuable to us than the
      gold mines of  California, 189.
    unjust condemnation of, by prominent writers,
      for want of knowledge how to use them, 189.
Sunlight.
    important for hospitals, 138.
    objected to by fashionable ladies, 162.
Sun's rays.
    do not heat pure air, 29.
    do not heat the  atmosphere  but heat a board
      fence, 104.
Sun's rays.
    the great moving and growing power, 28.
Sunshine.
    nature's great purifier, 162.
    too much excluded from Westtown boarding
      school, 158.
Surgeon-Generats patient probably killed by foul
      air, 76.

                      T.
Temperature.
    nothing to do with purity of air, 35.
    of human body remains uniform, 95.
Tenant houses.
    extract from Tribune, 165.
    sets of dens, 165.
    view of, in New York, 166.
Thermometer.
    in snowbank heated to 180° by sun's rays, 104.
    no indication of temperature of air, 110.
Treasury building, Washington,  127.
    2,500 high salaried clerks feed on sewer gas and
      smoke from forging fires, 133.
Treasury poison proverbial amongst Washington
      physicians,  134.
Turkey roasted philosophically, 105.

                      U.
Underground air-ducts.
    at Marine Hospital, Philadelphia,  objection-
      able, 140.
    for fresh air objectionable, 133.

                      Y.
Yankee way of sitting, 107.

                      V.
Ventilation.
    as influenced by air of different temperatures,
      35.
    defects,  new houses Parliament, 36.
    defects, new Yale College, 36.
    Dr. Franklin's theory of, correct, 40.
    experiments showing where required at ceiling
      and where at floor, 25.
    experiments with colored liquids, 36.
    extract from Carpenter's Physiology, 83.
    fireplace good for, 26.
    frescoed ventilator on ceiling of church, 58.
    general  want of, revealed by inspection of all
      offices from Delaware to Schuylkill, 49.
    how to ventilate a room in the evening, 52.
    how to ventilate  a room in the morning, 62.
    its importance  to life assurance  societies—
      60,000 feet every minute at Equitable, 206.
    more lectures on, needed, 82.
    must be changed when heating by radiation, 43.
    national apathy in regard to, 113.
    never have thought about it, 112.
    of bedrooms, 21.
    of church in neighborhood of lecture-room, 58.
    of latrines, 175. 
226
INDEX.
Ventilation.
    requires twenty-five cubic feet per minute for
      each person, 94.
    the theory that breath rises incorrect, 24.
    the  doctors  say, is better  than medicine for
      preventing disease, 85.
    the  ever-varying condition of  body and sur-
      rounding circumstances require separate in-
      telligent thought, 51.
    want of, in cars, 48.
    want of, in Cooper Union building, 50.
    want of, in Franklin Institute, 50.
    want of, in most public buildings, 50.
    want of, in school houses, 59.
Ventilation and cooling, 201.
Ventilating flues should not be used for smoke, 157.
Ventilating shaft.
    around kitchen chimney,  63.
    for school house, 163.
    generally too small to be of any use,  64.
    in Government hospitals, 175.
    in hospitals four feet by six feet, 64.
    large one for city dwelling, 200.
    one foot area for ten children, 163.
    should be placed near water-closets,  186.
    St. Ann's Church, five feet by five feet each, 152.
Vetitilating shaft.
    thoroughly tested during the late war, 64.
Ventilating stoves, fresh air for, must be conducted
      to top of, 192.
Ventilators at top, can remain open, 110.

                       W.
Warm air, false theories in connection with heat-
      ing by, 35.
Warming and ventilation always much trouble,
      177.
Warmth of body in excess of  the surrounding tem-
      perature a fundamental  condition  of our
      existence, 190.
Water-closets.
    separate ventilating shafts must be provided
      for, 182.
    ventilated by heated shaft, U. S. Treasury, 137"
    ventilation of, at Equitable, 206.
Westtown Boarding-school, plans of, 156.
Windows.
    are the great natural ventilators, 43. *
    should always lower from top,  52.
    simple method of lowering, 52.
Windows and doors best summer ventilators, 52, 64.
Without food, pure air kills sooner than foul, 77. 
 
342.9 
 
ond Wellore, Public
Health Service
Bethesdo, Md
US Department o\
Health.  Education,
and Welfare. Public
Health Service
Belhesda, Md.
U.S.Department of
    r*2 
NATIONAL  LIBRARY OF MEDICINE
NATIONAL  LIBRARY OF MEDICINE
NATIONAL  IIBRARY OF MEDICir 
:'?Kir:i