No.   88   Liberty  Street.
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Gentlemen :
              Allow me to  call your attention to my new device  for handling large volumes of air for
ventilation—approved by sundry experts, some of whom  are connected with both the Naval and Treasury
departments of our Government.
      An  engineer of celebrity in the Navy, says: "Green's new  method of ventilation will eventually
supersede all  of the old methods, producing an entire revolution in such matters."

                          NATURAL  METHODS  OF VENTILATION.

          ALSO MECHANICAL METHODS RELYING UPON THE WIND TO OPERATE THEM.
      All natural methods of Ventilation—also all mechanical methods relying upon  the wind as a power to
operate them—such  as Windmill Fans put upon  the tops of buildings for purposes of Exhaustion only,
must necessarily fail, not only for the reason that no means are provided to send into the building cool fresh
air in summer, and heated fresh air in winter, but in a calm, or with but a slight movement of the air on the
outside, they lose their power and  so fail to operate; such failure occurring at the very time when an active
ventilation is  most needed, it is no marvel that complaints are repeatedly heaped upon the head of him, who,
knowing  better,  persuaded the less informed to invest in a method of ventilation which must of necessity
prove to be a  perpetual failure.

                     ORDINARY  FAN-BLOWERS  FOR  VENTILATION.
      In  the  use of  ordinary Fan-Blowers for  ventilation, it  is  quite evident that in  most  cases parties
furnishing the plans and executing the same (using the Blowers only to send fresh air into the rooms, and
making no provision to eject the foul air from the rooms), do not get before their minds the full thought
upon the subject of ventilation, to  wit: that a positive and constant  circulation must be obtained to secure
a perfect  ventilation, and that such circulation  cannot  be obtained in velocities as required, except by an
injection of fresh  air into the room, and an ejection of the  heated foul air from the room, with the ability of
operating both at the same time, and by the same power.  The use of the Blower during the summer, under
the half thought  as aforenamed (only injecting fresh air into the rooms), may  be worked in connection with
a tolerable circulation, when  the  weather will admit of the opening of the windows and doors to allow the
heated foul air to escape, but when cold weather comes and the Blower can be used only to send in heated
air and the windows and doors cannot be opened as in  summer, what then?  Of course, an accumulation
of heated  foul air until the atmosphere becomes oppressive, when, to get a circulation, the windows are
thrown open, and a draft of cold air is allowed to enter, to the discomfort and possible injury to  many. Then 
EXPLANATION   OF   ENGRAVING,
                                Figs.  1,  2, 3,  4.
     The two prominent mechanical devices as seen in cut, are a Steam Air Pump, and a new and peculiar
Automatic Air Nozzle used for multiplying volumes of air sent into or out of the building to be ventilated.

                              Steam Air Pump, or Compresser.

      The Air Pump, or Compressor, is so common it needs no explanation, except  that it is of the same
general construction as are the Steam Water Pumps, the only difference being, the cylinder for air is arranged
with valves especially designed for air, but still  in case of accident to  ship it may be used for water, or as a
bilge Pump in freeing ship.
                                   Automatic Air  Nozzles.
      The Air Nozzles, A, Figs. 1 and 2, are provided with a valve, B, having an elongated tapering por-
tion, b, and a stem, a,  furnished with a spring which is set or compressed to a given pressure.  The valve is
surrounded with a series of short radial ribs,  having grooves between them which increase in depth toward
the inner end of the valve.  It will thus be seen  that as the valve is pushed out to the pressure desired, and
is discharging a full volume of air at a given number of strokes, and the pump is now slowed, by which only
one-half the quantity of air passes through the nozzle, the spring begins to act at once, and draws back the
valve, and  so adjusts the  opening of the nozzle  to the half  volume going out,  retaining by such automatic
device the  same or corresponding pressure on the less, that was expended on the greater volume, and so a
corresponding efficiency of induction is given to the half  or lesser  volume by such automatically adjusting
pressure.
                         Apparatus as  Applied to Building, Fig. 3.

                  INJECTION OF FRESH AIR  INTO THE BII1.DING.

      For  INJECTION the Air  Pump sends its quota  of air through the left branch of pipe, D, to the
Injector Nozzle, A, in basement, and forces it through said  nozzle at a given pressure (seldom over 5 lbs. to
the square inch), which volume bears the relation of only about three per cent, to the whole quantity of air to
be moved, the other 97 parts being drawn from the air shaft below, and passing on the outside of said nozzle
is made  to join  the 3 per cent, of air from pump,  making  a total of  100 parts, which, by the power of the
combined velocity and volume of air passing through said nozzles, is injected into and  through pipe C, to
the apartments of each story.

                  EJECTION OF HEATED FOXJI* AIR FROM THE BUILDING.

      In  the process of EJECTION, the Pump sends its quota of air through the right-hand branch  of pipe
D, which extends to the Ejector Nozzle, A, in the ventilating shaft, E, at the top of the building, and said
ventilating shaft, E, communicating  with registers e, in  ceilings or  walls of different apartments, the  air
from pump, passing through said ejector nozzle, A, with  the same power of velocity and volume combined
as described in process of "Injection," induces a strong upward current or draught, which draws the heated
foul air from the apartments, and throws it out through ventilating  shaft, E, at top of building.

                                     Steamship, Fig. 4,

      Shows in a limited way only the application to the  hold of a ship.   The Air Pump is supposed to be
located in  the Engine Room, and sending its air forward  by a small pipe seen under second  deck, which
passing up to  a pipe under main deck, it branches each way, running forward to nozzle located in ventilating
shaft F  which nozzle, pointing downward, injects fresh air into the hold, and the branch  running  aft
connects  with nozzle in ventilating shaft, F, which nozzle,  pointing  upwards, ejects the foul  air from  the
hold securing ample ventilation with the hatches closed.   Also applicable to all parts of the ship. 
D.  C. GREEN'S  NEW SYSTEM  OF VENTILATION,
Patented November, 1879.
999825
�1430913 
complaints are justly  made  by the parties suffering, and  the  windows are closed, when'the room is soon
filled again with heated foul  air, only to repeat the discomforts and injuries as aforenamed.
      The Blowers, then, as  now used, executing only one-half of the full thought as aforenamed, and not
suited to the execution in full as described, have thus far failed to give satisfaction in cases where a  thorough
and complete  ventilation is required.          ^

                       THE  D.  C. GREEN VENTILATING APPARATUS.

      In working my apparatus (as per engraving on third page), I use steam power in connection with  a
direct acting Pressure Air Pump, in its most simple form (without shafting pulleys or belts), by  which I  can at
will, inject fresh air into the room  or rooms, and at the same time eject the heated  foul air from the room, and
so  by either  a perceptible  or imperceptible circulation as may be desired, secure a perfect  condition of
ventilation, all of which is accomplished with windoivs and doors closed.   Furthermore, by said  illustrated
engraving, it  will be  seen, that my process enables me to send  the  compressed air from pump  to my air-
 nozzles through small wrought iron pipes, not only to  any part of building in which  the pump  is located,
 but also  to buildings adjoining  or more remote;  operating the nozzles in each and all for injection and
ejection, with equal ventilating efficiency as when applied to nozzles located in proximity with pump.
       Such universality of  application which I claim for my apparatus over  all others, also without the
 cumbersome  attachments of large lengthy air-pipes usually affixed to the ordinary blower; it will be seen,
that my apparatus is not only  superior for all purposes of  general ventilation, but  that it stands alone in its
 simplicity of  application, ample ability with economy to meet the following peculiar demands in the line of
forcing draughts for both ventilation and combustion, to  wit :
       First.—All flues found  in both  public and private  buildings, say court and school-houses, hospitals,
 public halls, hotels, banks, stores, etc.,  designed for ventilation, but found inactive because of adverse atmos-
 pheres or wrong construction—ventilating  shafts  already constructed,  into which air  pipes are  led  either to
 receive fresh  air or discharge foul air; also chimneys with, perhaps, long horizontal subterranean  passages
 requiring additional draught for combustion, all such are made efficient by the application of my apparetus.
       Second.—Eminently adapted to the  wants  of steamships, where room cannot be given for the cumber-
 some methods of ordinary blower ventilation.  All air pipes on ships found to be inefficient at a time when
 air below is most needed, are put in constant and efficient service by carrying compressed air in small wr ought
 iron pipes from air-pump to air nozzles wherever located in said air-pipes, and so at such points whether near
 or remote from pump, inject into ship or eject from ship currents of air in greater or less quantities as desired,
 securing at all times, whether in a calm or a blow, conditions  of ventilation suited to the comfort  and health
 of passengers in cabin or forecastle—also maintain  a circulation in hold of ship for the wants of cattle, fruits
 or other perishable freights—all of which  may be accomplished with cabins and hatches tightly closed, and
 so my  device is eminently adapted to ship ventilation.
       In conclusion,  I offer  my apparatus and methods of ventilation  to meet every conceivable want in such
 line, with the least incumbrance from  pipes and machinery, combined with the greatest possible efficiency
 and economy.
        It  will give me pleasure to show you my apparatus in operation at my office, No. 88 Liberty  Street,
 two doors west of Broadway.
                                            Respectfully yours,

                                                                   D.  C.  GREEN,
                                                     For the  D. C.  Green  Ventilating Company.

      p s.—A note to me naming day and hour of an intended call, will receive my special attention.  Usually in office from 12 M.
 to 2 P. M.



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