1870-71.] 
CITY DOCUMENT. 
[No. 30. 
PROVIDENCE WATER WORKS. 
OF THE 
CHIEF ENGINEER. 
JANUARY, 1871. 
PROVIDENCE : 
HAMMOND, ANGELL & CO., PRINTERS TO THE CITY, 
1871. PROVIDENCE WATER WORKS. 
Office of the Chief Engineer, / 
Providence, January 2, 1871. f 
To Messrs. M. B. Lockwood, 
Charles E. Carpenter, 
Joseph J. Cooke, 
Water Commissioners of the City of Providence. 
Gentlemen :-I respectfully submit the first formal report 
upon the work done under my direction during the last 
fifteen months. 
Having assumed the duties to which you appointed me, in 
October, 1869, I first gave attention to those parts of the work 
likely to require the longest time for their execution, and 
caused surveys to be made on Sockanosset Hill, with refer- 
ence to the definite location and plan of construction of the 
principal reservoir; and on the grounds selected for a pump- 
ing station, with reference to their best treatment for that pur- 
pose. 
In considering the construction of a reservoir, two 
of considerable importance were to be settled. The principal 
one, as to the necessity for making filter-beds in connection 4 
PROVIDENCE WATER WORKS. 
with the reservoir, had received considerable attention from 
yourselves, and the course of your deliberations tended to a 
very careful inquiry into all the plans that could be adopted 
for filtering the water, and to such an arrangement of the 
work, if possible, as would allow the decision of the question 
of the construction of expensive artificial filter-beds to be 
delayed until after the first introduction of water into the 
city. 
During your earnest consideration of the matter, the plan 
occurred to me of using as a natural filter, the sand, over and 
through which the river flows, making it available by excavat- 
ing basins near the river, and below the level of its surface. 
This plan was favorably received by you, and as our prelimina- 
ry examinations were satisfactory, the scheme was accepted as a 
happy settlement of the question ; whereupon all discussion 
of the subject ceased. 
The second question, as to whether the reservoir should be 
constructed in two parts on Sockanosset Hill, or have one part 
transferred to a suitable location in the city, was somewhat 
involved with the first; for, in the scheme proposed by the 
Committee of the City Council, and taken as a general guide 
for our plans, the line of filter-beds occupied the place of a 
division embankment between the two portions of the reser- 
voir. 
The subject of filtration was discussed in the report to the 
Committee of the City Council, above referred to ; and though 
the full estimates for each plan of supply included the cost 
of filter-beds, their construction, while inferentially, was not 
specially recommended, but was left for future decision, as 
may be seen by this quotation:-"In regard to any of the 
waters recommended for the supply of the City of Provi- 
dence, the amount of soluble matter in them is so very small, 
so much less than in the best of wells, that it would seem to 
be superfluous to filter them for the sake of reducing this 
amount. And, so far as practical utility is concerned, the 
same may be said of separating the small amount of sus- 
pended matter left after passing the settling basin. But, in CHIEF ENGINEER'S REPORT. 
5 
case extraordinary purity should be desired, the plans submit- 
ted embrace provision for filtration, which may be adopted or 
not at pleasure." Whether there are some subtile and inju- 
rious elements, undiscoverable, or at least undiscovered by 
ordinary chemical tests, and common to all waters, available 
for public supply, which would be affected by thorough filtra- 
tion, is not discussed ; and, indeed, our present knowledge of 
the matter is hardly sufficient to allow of its intelligent discus- 
sion. 
The matter which it seems desirable to have removed from 
the Pawtuxet water has, for the most part, very little weight 
or substance, but is simply a coloring matter, coming, I have 
no doubt, from autumn leaves, and of similar nature, probably, 
to the coloring matter of that common beverage, tea, and 
having no injurious quality, so far as known, though it is 
objectionable to the eye. 
This appears only during certain portions of the year, 
and is of such delicate fineness as to make it doubtful 
whether filtering, through the ordinary artificial filter-beds, 
would remove it. To test this, a small filter was con- 
structed, as nearly as practicable, of similar materials and 
with the same arrangement as would be used in large 
filters, and having a surface area of one square yard, through 
which the water of the Pawtuxet river, at the Pontiac Mills, 
was allowed to flow at about the same rate as would be adopt- 
ed in practice, or about eight inches per hour. It was also run 
at a slower rate than this a portion of the time. The water 
flowing from this filter was at intervals compared with that in 
the river, and it was found that while the amount of coloring 
- matter was considerably reduced, it was not at any time en- 
tirely removed. 
A comparison of this water was also conveniently made 
with the water of a large well excavated in the sand, near the 
bank of the Pawtuxet river, at Pontiac, and largely supplied, 
I suppose, by the river water filtered through the sand. It 
was found that the artificially filtered water had, in compari- 
son, considerable color, though I was much struck by the 6 
PROVIDENCE WATER WORKS. 
remarkable clearness of the well water, both as seen in the 
beaker glass and in a large body. Professor Appleton has 
since told me that he has found this water to be almost pre- 
cisely like the Pawtuxet, differing only as water slowly filter- 
ing through a large body of sand would be expected to differ; 
that is, having a little less vegetable and a little more mineral 
matter, with slightly increased hardness. If, as seems very 
probable, this well water is in great measure the naturally fil- 
tered Pawtuxet water, it furnishes strong evidence that the 
coloring matter can be removed by natural filtration through 
sand, on a still larger scale. 
While the artificial filter tests were going on, examinations 
were being made in the sand basin through which the river 
flows, near the proposed site for the pumping station, by dig- 
ging test-pits; by drawing the sand up through small tubes 
reaching a depth of ten or twelve feet; and by sinking 
artesian wells to the depth of sixty feet, more or less, by 
the use of eight-inch iron pipes, which were afterwards with- 
drawn. Eighteen of the latter, and a great number of the 
other tests were made; and the character of the material to be 
removed from the water, the probable inclination of the 
water-table, the probable effect of the motion of the water 
upon the stability of the sand, and of the distance of sand 
passed through upon the color of the water, were carefully 
considered. 
The result of all these investigations led me to the conclu- 
sion that the material was well suited for use as a natural 
filter, and that the probability of obtaining a sufficient 
quantity of clear water from basins excavated in the sand, at 
a depth below the surface of the river, at a comparatively 
small expense, and without permanent clogging, was so great 
as to leave little or no doubt of our duty to use it rather than 
to incur the great expense and constant care attendant upon 
artificial filter-beds, which did not promise to be so effectual 
for our purpose ; and this, notwithstanding the possible chance 
of failure in the scheme, and the possible need of construct- 
ing the artificial filter-beds at last. Even, however, should CHIEF ENGINEER'S REPORT. 
7 
it fail as a natural filter basin, it would probably be 
worth a considerable portion of its cost as a settling basin, 
from which the water, in this case introduced into it by pipes 
running through the river embankment, would be pumped. 
This project having, as before stated, received your approv- 
al, the plans of the Sockanosset reservoir were designed for its 
construction without filter-beds, but were so arranged as to 
admit of their construction at some future time, if found neces- 
sary, without much interference with the operation of the 
works, nor much extra expense on account of their being sub- 
sequently built. Their proposed location is on the northerly 
side of the reservoir, where the land is well adapted forthem; 
and openings have been left in both the inlet and outlet cham- 
bers for the connection of conduits leading to and from the 
proposed site. 
In regard to the construction of a reservoir within the city, 
it was necessary to secure a suitable site for it, at such an ele- 
vation as would admit of its use in connection with Socka- 
nosset reservoir. Such a site was found at the corner of Hope 
and Olney streets, and within the square formed with those 
streets by Barnes and Prospect streets. 
One of the chief advantages to be gained by such a reser- 
voir is its action as a regulator in connection with the daily 
use of water in the city. 
Another advantage to be gained by it, is the storage of a con- 
siderable quantity of water, near the place of consumption, 
which could be relied upon for use during a possible stoppage 
of supply by accident to the leading mains or from other 
cause. 
The use of such a reservoir, as a regulator, will render a 
thirty-inch main of about equal value for the supply of the 
city as a thirty-six inch main without such regulator. The 
reason for this lies in the fact, that the consumption of water 
in the city, during certain hours of the day, is often about 
fifty per cent, greater than the average hourly consumption, 
and sometimes much more than that. At times, also, for a 8 
PROVIDENCE WATER WORKS. 
whole day the demand is about fifty per cent greater than the 
average ; and occasionally for an entire month, it is one-third 
greater than the average for the year, with exceptions of even 
greater monthly consumption. Therefore, a leading main from 
a reservoir, at a distance of several miles on one side is re- 
quired to be of greater capacity, in order to supply the greatest 
demand without too much loss of head, tinder that rate of 
flow; but, with another reservoir lying beyond the centre of 
distribution, near at hand, on the opposite side, a leading main 
may be of such size as to supply the average demand; for. 
when the draft upon the main exceeds the average quantity, 
so as to lessen the head upon the pipes, a supply begins to 
flow from the regulating, or storage reservoir, and thus the 
demand is supplied from both directions, through pipes of a 
combined capacity, sufficient to maintain the required head. 
Again, when the draft becomes less than the average quantity, 
the head upon the pipes increases, and the water overflows 
into the regulating reservoir and is stored there for use during 
the greater demand. 
The saving of expense by such a reduction in the size of 
leading mains was estimated to be nearly sufficient, together 
with the amount saved by the construction of a single, instead 
of a double reservoir on Sockanosset hill, to construct the 
additional reservoir, and to pay for the land on which to build 
it, leaving the other important advantages of this plan to be 
gained at a very moderate cost. This view of the matter de- 
termined you to adopt the plan for two reservoirs, leav- 
ing a single, simple reservoir to be built on Sockanosset hill. 
Having determined the general character of the reservoir 
to be constructed at that place, and having obtained the neces- 
sary levels and contour lines, and learned something of the 
character of the ground by test-pits, we endeavored to so plan 
the work, in shape and dimensions, as to give the greatest 
capacity for the least relative cost. This required that the 
high-water level should be placed four and one-half feet higher 
than was proposed in the report to the Committee, for the CHIEF ENGINEER'S REPORT. 
9 
receiving portion of the reservoir, and six and one-half feet 
higher than the distributing portion, or at an elevation of 
one hundred and eighty and one-half feet above high tide. 
The plan of the reservoir is pyriform, to suit the character 
of the ground; it is about one thousand feet long and eight 
hundred and sixty feet wide at the base. 
The area covered by the reservoir and embank- 
ment is 14.0719 acres. 
The area of the reservoir bottom is - - 9.5383 acres. 
The area of the high water surface is - 10.9467 acres. 
The length of embankment, on the centre line, is 2,885.29 feet. 
The length of the high water line, including 
lines on wing walls, is - - - - 2,873.33 feet. 
The capacity of the reservoir is - - 51,156,544 gal- 
' Ions, U. S. standard. 
The embankment is of earth, nineteen feet high above the 
bottom of the reservoir, and fifteen feet wide at the top, ex- 
cept where widened out near the inlet and outlet chambers, 
with side slopes of one and one half to one, or, in other words, 
running off a horizontal distance fifty per cent, greater than 
the height. The high water surface will be four feet below 
the top of the embankment. 
The bottom, of the reservoir, slopes from the foot of the em- 
bankment to the bottom of the outlet chamber, which is one 
foot lower, to give facility for drainage. The embankment is 
formed of earth taken from the excavation, which, as a whole, 
is well adapted for the purpose, but lying as it does in masses 
of very different character, it requires to be very thoroughly 
mixed to get the best results. So much of the surface soil as 
was required to cover the outer slope and top of the embank- 
ment to a depth of one foot, was reserved in spoil banks for 
that purpose. The rest of the soil was mixed with other earth 
for the embankment. 
The material used for puddle was also taken from the exca- 
vation, the largest portion of it being of a hard, compact char- 10 
PROVIDENCE WATER WORKS. 
acter, the grains forming it being hard and sharp, and varying 
in size from an almost inpalpable powder to coarse grained 
sand or crushed stone, and found, by experiment, not to shrink 
in working. This was thoroughly mixed with a smaller 
portion of yellowish subsoil, and when well compacted 
made a very hard and apparently impervious mass. As found 
in the excavation, the material contained great numbers of 
stones considered too large to go into the puddle-wall. The 
most expeditious and effectual way to remove them seemed to 
be by screening through wire nettings of such sized mesh as to 
remove all stones more than one inch in diameter, which was 
accordingly done. 
Experiments were made upon the two principal kinds of 
material found on the work, to ascertain what amount of 
shrinkage was to be expected from excavation to embankment; 
observations were also made upon the amount of void spaces 
contained in certain materials, as a means of judging what 
amount of finer material it would be necessary to mix with 
that, to make the most compact mass. 
What is called heavy material, on the work, did not shrink 
at all, in the experiments. This was supposed to form about 
three-fifths of the excavation. The other, lighter material, 
supposed to form about two-fifths of the excavation, shrunk 
about thirteen per cent, of its bulk. 
The estimated loss in the removal of stumps was about one 
thousand cubic yards, and that from the removal of grass roots 
and other vegetable matter was about eighteen hundred cubic 
yards. 
The total estimated loss and shrinkage of material amounted 
to about nine and one-third per cent, on the total amount of 
excavation. 
Three samples of sand, brought-from a distance and used 
for concrete and mortar about the inlet and outlet chambers, 
were found, by measurement with water, to have void spaces 
amounting, in two cases, to thirty-six per cent, and in the 
other case to thirty-seven per cent, of the whole bulk. 
Three samples of stone, suitable for concrete, which had been 
screened from the earth used for puddle, had in two cases forty- CHIEF ENGINEER'S REPORT. 
11 
two per cent, and in the other case forty-four per cent, of void 
spaces. 
Three samples of broken stone, suitable for concrete, were 
found in each case to have fifty per cent, of void spaces. 
Three samples of sand, brought from a distance, now on the 
work and yet to be used, were found to have, in two cases thirty 
per cent and in the third, thirty-one per cent of void spaces. 
The surface soil, roots, loose stones, and other unsuitable 
material, were removed from the site of the embankment, so 
as to expose a suitable material on which the embankment 
could be raised. The amount of material thus removed was 
greater or less in different places. 
The trench for the puddle wall was cut deeper than the 
general surface, for the foot of the embankment, and stepped 
on the sides to a narrow trench at the bottom. 
A trench was also dug for puddle at the foot of the interior 
embankment slopes, six and one half feet wide and three and 
three quarters feet deep, from which the puddle was carried, 
in a layer two feet deep, over the natural earth, until it met 
and was joined with the vertical puddle wall in the interior of 
the embankment. 
The material for puddle was applied in layers six inches in 
thickness, then properly moistened and thoroughly compacted 
by a grooved roller or by ramming, which compressed the lay- 
ers to a thickness of about four inches. 
The earth for embankment was applied in layers seven to 
nine inches in thickness, which, when properly moistened and 
well rolled with the grooved roller, were compressed to layers 
of about six inches in thickness. 
The layers were so applied as to keep the sides of the em- 
bankment higher than the middle, forming a concave or dish- 
ing surface. 
The earth embankment and puddle wall have been carried 
very nearly to the required height for soiling, excepting on 
the easterly side, between and about the inlet and outlet gate- 
chambers, and on a portion of the northerly side where the sur- 
face is at present about five and one half feet below such re- 
quired height. 12 
PROVIDENCE WATER WORKS. 
The interior slope of the embankment is to be lined with a 
layer of broken stone six inches thick, and a close, dry pave- 
ment of split stone over that, fifteen inches thick, with a con- 
crete footing and coping. 
The inlet chamber is at the south end of the reservoir, and 
the outlet chamber at the northeasterly extremity. They are 
to be connected by a brick conduit of four feet interior diam- 
eter and about nine hundred feet long, laid in the embankment 
outside of the puddle wall. 
The bodies of the gate-chambers and wing walls are formed 
of rubble masonry laid in cement mortar, the exposed portion 
of the wing walls being laid with quarry-faced granite ashlar, 
and the piers and exposed faces of the chambers in dressed 
granite ashlar. The chambers are to be lined, after the work 
is thoroughly settled, with hard brick, of which the division 
walls and gate settings are also to be constructed. 
Three lines of thirty-six inch pipes are laid under the em- 
bankment, to be used for force mains, terminating in sepa- 
rate cells within the inlet chamber, from which the water 
can at pleasure be turned into the reservoir or into the 
conduit connecting the two chambers. The outlet chamber 
is arranged with three cells in a similar way, with which 
thirty-six inch pipes are connected for leading mains. After 
passing through the embankment, these pipes will be reduced 
to thirty inch, or one or more of the leading mains may, in 
the future, be laid of the full size, into the city, if it is found 
desirable. 
Arrangements are made so that water can be drawn into the 
leading mains from near the surface of the reservoir or near 
the bottom, at pleasure. 
The stone masonry included in the contract is completed ex- 
cept in minor particulars. 
It remains for you to contract for the brick masonry and the 
buildings proposed to be erected over the gate-chamber, the 
plans for which have been prepared. 
The gates, ways &c., are under contract, but not much pro- 
ress has been made towards their construction, as they will 
not be needed before next summer. chief engineer's report. 
13 
The general work on the reservoir was closed on the twelfth 
day of December, but the stone breaker is kept at work crush- 
ing stone for concrete, road-metal and slope lining, and men 
are also engaged preparing stone for the slope-paving. It is 
proposed that this work shall go on through the winter. 
Measures have been taken to secure the reservoir embank- 
ment from injury by washing during the winter. 
Owing to the very mild weather during the autumn and 
early winter, the earth work was carried on much later 
in the season than could have been reasonably expected ; but 
on many mornings the surface was found slightly frozen, and 
considerable expense was incurred by the contractor in re- 
moving earth from the puddle, and in breaking up the surface 
of embankment to fit it for proper incorporation with material 
to be put on during the day. Coarse salt was sometimes 
strewn over the surface, on leaving the work, and where used 
in sufficient quantity it was very effectual in keeping out the 
frost By preparing enough surface in this way for work in 
the early morning, time was gained for the sun to act upon 
other surfaces which were to be covered during the day, and 
thus the whole expense, compared with the work done, was 
not excessive. 
The whole amount of work done upon the reservoir from 
the fourth day of May to the twelfth day of December inclu- 
sive, as estimated for payment, was:- 
91,959 cubic yards Earth Excavation 
at 
$ 36 
1,626 
g 
G 
Rock " 
G 
2 00 
16,347 
G 
G 
Puddle 
G - 
40 
59 
G 
G 
Concrete 
G _ 
8 00 
10 
G 
G 
Broken Stone 
G _ - 
3 00 
784 
G 
G 
Rubble Masonry 
G _ 
9 00 
29.5 
G 
G 
Cut-faced Ashlar 
G _ _ 
80 00 
46.5 
G 
G 
Quarry-faced Ashlar at 
50 00 
46 lineal feet 
Drain Culvert 
G _ 
4 00 
Setting 18 36 inch Iron Pipes, and 9 special castings for 550 00 
In addition to the above, about forty-five hundred cubic 
yards of stone, suitable for concrete, slope-lining and road-metal, 14 
PROVIDENCE WATER WORKS. 
Were broken or screened from puddle, on which thirty-one 
hundred dollars have been advanced to the contractor, on ac- 
count No estimate has been made for the slope-paving pre- 
pared, nor for sand delivered. 
The work at the pumping-station, and on the line of force- 
mains, has consisted mainly of excavation for the foundation 
of the engine house, to the level of the water-table; the con- 
struction of a sand embankment along the bank of the river, 
dividing the channel from the site of the proposed filter-basin, 
excavation to a small extent within that basin and for a road 
leading around it; the construction of two brick culverts of 
five feet and one of four feet interior diameter, with granite 
heads and wing-walls; the formation of three sections of high 
embankment for the force-main line, from cuts on the line and 
borrow-pits near, and the partial excavation of a roadway from 
the pipe line to the Pontiac road, and the construction of a 
highway bridge on the Pontiac road over the pipe line. 
In addition to the labor of laying out and caring for this 
Work, the engineering party stationed at Pettaconset has made 
surveys of most of the lands purchased or taken for water 
works purposes, and laid out for and superintended the con- 
struction of so much of the three dwelling-houses, being erected 
for the employees, as has thus far been executed. 
Of the sand used for mortar at the pumping station, two 
samples were found by measurement to have, the one forty-two 
and five tenths per cent., the other forty-two and one tenth per 
cent, of void spaces. The measurement was made by filling a 
box containing one cubic foot, and accurately measuring the 
amount of water which the box would contain in addition to the 
sand. The sand was filled into the box at about the same de- 
gree of compactness as if measured for mortar in the ordinary 
way. Another sample, filled into the box until it was half full 
and then rammed, and having each shovelful after that rammed 
as it was put in, was found to have twenty-nine and two tenths 
per cent, of void spaces. 
Two samples of gravel usedin concrete were found to have, CHIEF ENGINEER'S REPORT. 
15 
the one twenty-nine and six tenths percent., the other twenty- 
seven nine tents per cent, of void spaces. 
A sample of screened gravel from one of the test-pits had 
thirty-nine and two tenths per cent., and a sample of screened 
sand had thirty-six and seven tenths per cent, of void spaces. 
A cast-iron pipe, eight inches in diameter, was sunk verti- 
cally near the middle of one of the proposed filter-basins to the 
depth of twenty four feet below the present surface of the 
ground, or about twenty-two feet below what we have assumed 
as the ordinary low-water stage of the river, and the bottom 
being open, the water is supposed to stand in the pipe at the 
same level as in the surrounding ground. A float was placed 
on the water in the pipe, carrying a point which rose and fell 
upon a gauge set to indicate the height of the water above tide 
level. Another gauge, also indicating the height above tide, 
is established at the river. The pipe is sunk at a point about 
one hundred and fifty feet from the bank of the river. 
The observations upon these gauges at the present state of 
the river, varying from seven to eight and one-half or nine 
feet above tide, indicate that the water in the land rises and falls 
with the water in the river as that rises and falls by the vary- 
ing quantity turned into it by the mills above, and that it even 
feels the check of the stream caused by the nooning at the mills, 
though the nearest of them are two or three miles up the river. 
When the river is carrying the least amount of water, as 
during the night or on Sunday, and running at about seven to 
seven and one-half feet above tide, the water in the pipe usu- 
ally stands from ten to seven inches higher than the water 
in the river. This difference in height depends upon the 
length of time during which the river is running at a low stage, 
and consequently upon the time given for the surface of the 
water in the land to fall from its steeper inclination, caused by 
the sudden fall in the river, towards the natural inclination 
which is due to the average supply of water passing from the 
land into the river at its low stage. But any rise or fall in 
the river,* even with this difference of elevation between it and 
the water of the well in the basin, is felt at the well within 
half an hour, causing a rise or fall there. 16 
PROVIDENCE WATER WORKS. 
In order to gain a fair knowledge of what had been adopted 
by diffeient engineers, and in different places, for the thickness 
and weight of water pipes, I gathered such formulae as could 
be conveniently obtained, and collated them in tabular form, 
and by profiles, and also compared by profiles the weights of 
water pipes of various sizes in actual use in many of the cities 
of the United States. 
The formulae used for the comparison of thicknesses as pro- 
posed or adopted by different engineers are as follows:- 
1. James B. Francis, t = .000058 II D + .0152 D + .312 
2. John Neville, t = .0010 (n + 10) D + .32 
3. M. Dupuis, t = .0016 n D + .013 D + .32 
4. John F. Ward, t = .0002 II D + .30 
5. James P. Kirkwood, t =--?-? + .40 
c-p 
.34 for G inch pipe. 
.33 " 8 " " 
G " " u t = ? i « u 12 " " 
c-p | .28 " 20 " " 
.25 " 30 " " 
. .24 " 36 " " 
7. Modification of ' r .40 for 6 <fc8in. pipe. 
Mons. Dupuis' .3912 " " 
formula sug- - t = 3.4 n (.0016 D) + .38 " 20 " " 
gested by Mr. I .37 " 30 " " 
Kirkwood, [ .36 " 36 " " 
8. J. F. D'Aubuisson, modified, t = .00025 II D + .39 
9. Wm. J. M. Rankine, t =_ /- the largest result 
V 48 . 
jq - 000 to used. CHIEF ENGINEER'S REPORT. 
17 
11. Tiros. J. Whitman, t = .0045 n D + .4 - .0011 D 
/v/ D \ HD 
12. Thomas Box, t = ( + .15 J + qqq 
5.37 for under 12 inch 
• .50 " 12 to 30 " 
.62 " 30 to 50 " 
14. Proposed, for diameters ) 
greater than 36 inches, j t = -00008 H D + .0125 D + .33 
15. Adopted, for Providence ■> - . 
Water Works, f * = 'O0008 H D + .01 D + .36 
t = thickness in inches. 
II = head in feet. 
D = diameter in inches. 
n = number of atmospheres of pressure at 33 feet each. 
p = pressure per square inch in pounds. 
r = radius of pipe in inches. 
c = cohesion of the iron, as allowed, being in No. 5 7,500, and in 
No. 6 5,000, pounds. 
The third formula, adopted in his practice by M. Dupuis, 
engineer of the Paris Water vVorks, is in the form given by 
Mr. Neville in his " Hydraulic Tables," etc, , 
Mr. Ward would, in no case, take H at less than 100. 
The eleventh, twelfth and thirteenth formulae are found in 
a little book of useful information issued by R. D. Wood 
& Co., of Philadelphia. 
The thicknesses of pipes as cast by Glasgow founders were 
also compared with the others, but I have no formulae for their 
expression. 18 
PROVIDENCE WATER WORKS. 
The weights of pipes compared, were those adopted as fol- 
lows :- 
By New Bedford, 
" New York, 
" Philadelphia, 
" Trenton, 
" San Francisco, 
" St. Louis, 
" Warren Foundry, Stock. 
By Baltimore, 
u Boston, 
" Brooklyn, 
" Cambridge, 
" Chelsea, 
" Chicago, 
" Newark, 
I trust that the result of these examinations and comparisons, 
as expressed in formulae Nos. 14 and 15, will prove to be per- 
fectly safe in our practice, and that we have not used more 
iron than ought properly to be used to insure such safety. 
The pipes for the force main and for the leading main, are 
cast in four classes, of different thicknesses, depending on the 
head of water to which they are to be subjected. Those for 
distribution are cast in two classes. 
The weights are estimated, at 0.261 lb. per cubic inch, for 
pipes measuring twelve feet in length, including the bells. A 
variation of four per cent, is allowed in the weights of single 
pipes, and the gross weight of the pipes of a given contract 
is allowed to exceed the standard weight two per cent, for 
each diameter. The weights of the several pipes are marked 
on them at the foundry, but they are re-weighed for payment, 
on receipt at the wharf in Providence. 
The following schedule gives the thickness and weight for 
each class of each diameter and the greatest proposed hydro- 
static head under which the pipes are to be used; CftlEE engineer's REPOR'I. 
19 
SCHEDULE. 
Nominal 
Diameter, 
Inches. 
Class. 
Thickness 
of Metal, 
Inches. 
Standard 
W eight, 
Pounds. 
Greatest 
Proposed 
Head. 
6 
B 
402 
180 
8 
A 
1 
533 
100 
8 
B 
A 
590 
180 
10 
A 
jli 
52 
700 
100 
10 
B 
19 
52 
772 
180 
12 
A 
9 
16 
885 
100 
12 
B 
2 1 
32 
1,016 
180 
14 
A 
1 S» 
52 
1,082 
100 
14 
B 
11 
16 
1,236 
180 
16 
A 
2 1 
52 
1,375 
100 
16 
B 
f 
1,533 
180 
18 
A 
11 
16 
1,594 
100 
18 
B 
25 
32 
1,789 
180 
20 
A 
2 a 
32 
1,852 
100 
20 
B 
H 
2,143 
180 
24 
A 
2,502 
100 
24 
B 
ia 
16 
2,850 
180 
30 
a 
13 
16 
3,155 
60 
30 
A 
it 
3,484 
100 
30 
b 
1 
3,809 
140 
30 
B 
i A 
4,026 
180 
36 
a 
1 
4,101 
60 
36 
A 
1 
4,627 
100 
36 
b 
li 
5,148 
140 
36 
B 
1 i 
5,667 
180 20 
PROVIDENCE WATER WORKS. 
The diameters are nominal, but no pipes or special castings 
have less interior diameter than that specified as nominal, and 
the thickest pipe approximates closely to that diameter. The 
exterior diameters of all classes, or thicknesses, of pipes are 
required to be the same for each specified nominal diameter, 
the variations in thickness of metal being made by changes 
in the interior diameter. 
The exterior diameters of the pipes, and the whole of the 
bells, being the same for every class, there is no trouble in 
laying pipes of one thickness in connection with those of 
another thickness. 
The depths of the bells are in proportion to the diameters 
the pipes, from two inches for the six-inch pipes, to four 
.ches for those of thirty-six inches diameter. The special 
castings have bells one inch deeper than is due to the diame- 
ters of the pipes to which they belong. 
All the pipes are cast vertically. The specifications require 
that they shall be cast with the bell end down, but as the fix- 
tures for small pipes were not fitted for it I allowed one foun- 
dry, on condition that a separate core be made for the bell, to 
make pipes of twelve inches diameter and less with that end 
up, resulting thus far in quite perfect and handsome castings, 
with unvarying depth of socket The plan of using a sepa- 
rate core is liked very much at the foundry, where it will prob- 
ably be adopted for small pipes in their general work. 
After being coated with coal-pitch varnish while hot, the 
pipes are subjected to hammer inspection while under a hydro- 
static pressure of three hundred pounds to a square inch. 
The tensile strain of the iron used was required to be at 
least sixteen thousand pounds per square inch, which is rather 
less than that usually specified, so far as I know ; but we had 
at first some trouble in getting specimens which would uni- 
formly bear this strain, though as now made the pipes are of 
rather stronger iron than we care, on account of the resulting 
change in brittleness, to have used. 
Some three hundred samples have been broken, and the 
ordinary range of strength is from about eighteen thousand 
to about twenty-eight thousand pounds to a square inch. CHIEF ENGINEER'S REPORT. 
21 
The specifications for the manufacture of pipes, on which the 
iron-founders bid, were carefully drawn, and required good 
pipe. Much complaint has been made in regard to the strict- 
ness of our adherence to the specifications, but no pipes have 
been rejected which were believed to be safe for our use, and it 
is hoped that our adherence to the requirements of the con- 
tracts may tend to improve the character of all the pipes we 
receive. 
The right of rejection for imperfections is good at all times 
until the final completion and adjustment of the contract. 
Much labor has been spent upon the plans for the location 
of the pipes, and the determination of their proper sizes. It 
has been our effort to so arrange the distribution as to deliver 
the water at its destination by the shortest practicable route, 
and at the same time to provide for a fair supply to all sec- 
tions in case of the main arteries to those sections being cut 
off temporarily by accident or otherwise. 
Estimates were made of the probable amount of water 
needed at present and prospectively in all sections of the city, 
and the smaller pipes were designed for a liberal supply for 
many years to come; leaving the larger mains, which will be 
needed when there is a largely increased demand,- to be added 
from time to time as they are required. 
As a guide in the determination of the most economical 
sizes for pipes, to carry certain quantities of water, I caused 
calculations to be made of the relative cost of pumping the 
water to an additional head necessary to carry a certain quan- 
tity of water through a small sized pipe, and cost of an 
increased size of pipe necessary to convey it at a less velocity, 
and consequently with less head. These calculations were 
based on an assumed uniform duty of 500,000 foot pounds 
per pound of coal, and a cost of nine dollars per short ton of 
coal burnt in the furnace. The cost of iron pipe is taken at 
fifty dollars per ton. The difference in cost of laying will 
not materially affect the question. The loss of head result- 22 
PROVIDENCE WATER WORKS. 
ing from greater velocity is calculated from Darcy's formula 
for new cast iron pipes. 
The result is as follows :- 
Diameters of Pipes. 
Greatest allowable velocity. 
6 inches 
2.526 feet per sec. 
8 " - 
2.405 " 
10 " 
2.583 " 
12 
2.904 " 
16 " 
2.929 " 
20 " - 
2.990 " 
24 " 
3.224 " 
30 
3.488 " " 
The 30 inch pipe is compared with a 36 inch. If the de- 
mand for water at a given point is such as to require a greater 
velocity than is given opposite a certain sized pipe, then the 
next larger sized pipe should be used in that place. 
As the velocities given are the greatest allowable for that 
size of pipe, and as the loss of head is based on experiments 
upon new pipes, free from rust and accretions, which will in- 
crease the loss of head, I have assumed two feet per second 
as a general guide for the velocity of flow in the distribution, 
and the sizes of the pipes have been determined accordingly. 
Perhaps a greater velocity might have been allowed in the 
larger pipes, but as the influence of those pipes extends over 
a greater area, and I understand it to be your wish to have all 
decisions lean towards a thorough efficiency in the work, it 
was thought best to adopt a uniform rate. This will also, by 
increasing the sizes of the larger mains, have a tendency 
to delay the increase in their number, which increase must, 
however, come at a later time. 
The contract for laying pipes required that 
cl 1,800 feet of 36 inch force main, 
27,150 feet of 30 inch leading main, and 
3,000 feet of 24 inch leading main, 
be completed on or before the first day of December last; but 
numerous causes, among them the non-receipt of pipes in the CHIEF ENGINEER'S REPORT. 
23 
order required, have tended to interfere with the work, an i 
it closed on the 30th of December, with the f ''owir ~ amounts 
laid 
Force Main, 36 inch pipe. 
From Station 21.26 to Station 38.004. 
29 pipes of class B. 352.42 feet 
81 " " " b, - - - 984.37 " 
10 " " " A. - - - 12L53 " 
18 " " " a. - - - 218.74 tt 
138 pipes. Total, - 1.677.06 feet laid. 
Average per pipe, 12.153 feet. 
Leading Main, 30 inch pipe. 
From Station 3.582 to Station 27.50. 
37 pipes of class a, 449.81 feet 
40 " " " A. - - - 486.28 " 
117 " " " b, - - - 1.422.37 " 
3 " " " B. - - - 36.47 
197 pipes. TotaL - 2.394.93 feet laid. 
Average per pipe. 12.157 feet 
From Station 39.89 to Station 91.38. 
159 pipes of class B, - - - 1.935.70 feet 
264 " " " b. - - - 3.213.50 " 
423 pipes. Total, - 5,149.26 feet laid. 
Average per pipe, 12.173 feet 24 
PROVIDENCE WATER WORKS. 
From Station 108.09 to Station 123. 
118 pipes of class b, 1,435.42 feet. 
4 " " " B, - - 48.65 " 
122 pipes. 1,484.07 " 
Add for two branches, - - 7.00 
Total, - 1,491.07 feet laid. 
Average per pipe, 12.164 feet. 
From Station 145.96 to Station 154.88. 
69 pipes of class b, 839.96 feet 
4 " " " B, - - ' - 48.69 " 
73 pipes. 888.65 " 
Add for one branch, - . - - 3.67 " 
Total, - 892.32 feet laid. 
Average per pipe, 12.173 feet. 
Total length of Leading Main laid, 9,927.58 feet. 
Summary. 
Total number of pipes laid, - - 953 
Total length of pipe laid, - - 11,593.97 feet. 
" " " branches, - - 10.67 " 
Total length of pipes and branches, - 11,604.64 feet laid. 
Force main, 1,677.06 ft. 36" pipe = 0.3176 miles. 
Leading " 9,927.58 " 30" pipe = 1.8802 " 
Total, - 11,604.64 " 2.1978 miles. 
The stationing is measured horizontally. 
Notwithstanding the delays which have occurred in laying 
the pipes during the past year it is supposed that we shall re- 
ceive all that are proposed to be laid next season in ample CHIEF ENGINEER'S REPORT. 
25 
time for the purpose, and that by employing four gangs of 
pipe layers we shall be able to put in, by the first of August, 
all that are now contracted to be laid. 
Though the pipe-laying is stopped for the present, the work 
of blasting for pipe trenches, on the force main and on the 
leading main, is still going on, and it is hoped that both these 
lines may be connected with the reservoir during the winter. 
About thirty-three thousand cubic yards of earth have been 
removed in grading for the highway on the line of leading 
main between the Reservoir and the Stonington Railroad. 
About eight thousand feet B.M. of sheet piling have been 
driven. About two hundred cubic yards of rubble and about 
six cubic yards of granite ashlar have been laid for the abut- 
ments of a bridge over the Pochasset river. These abutments 
were, by contract, to have been completed on the first day of 
November. About one fifth of the masonry is yet to be laid. 
The other materials, excepting two wrought iron girders, are 
ready for the completion of an iron bridge as soon as the abut- 
ments are finished. 
Very careful and elaborate investigations have been made 
in regard to pumping engines, and considerable progress has 
been attained in the plans for them. A mistake in this matter 
might be disastrous, and any gain in efficiency or simplicity, 
without loss in other respects, would be very valuable and well 
worth great efforts to obtain. We shall gain time for 
thorough and complete designs, by putting up a temporary en- 
gine for the first supply of the city. Such an engine is now 
in process of construction by Mr. Henry R. Worthington, of 
New York, under contract for its completion in running order 
on the first of next August. Your conclusion to put up this 
temporary engine has, I think, made the introduction of water 
into the city during this year very probable, and has relieved 
us of many disadvantages which would attend the construction 
of permanent engines, with adequate wells and foundations, 
within so short a time. 26 
CITY OF PROVIDENCE. 
Designs have been made in our office for the valves, or gates, 
to be used in the distribution and on the mains, and speci- 
mens of eight inch and twenty-four inch sizes for use in North 
Main street are in process of construction. 
Bids have been received from three competent manufactur- 
ing parties for making the whole number required, and bids 
are expected from two others within a few days. It is believed 
that such data as you will require, in order to contract for 
these important parts of the work, can be furnished within a 
short time and in good season for their completion before they 
will be needed. 
The valve is designed to be parallel-faced, with a single disk, 
which will drop below the pipe for all sizes more than twelve 
inches in diameter, and rise above it for those of twelve inches 
and under. In these respects the valve is not new. 
We have also made designs for the construction of a hy- 
drant, which it is hoped will combine many of the advantages, 
and be free from some of the disadvantages, of the hydrants 
now in use. 
Its location will be on the sidewalk, just inside the curb- 
stone, and it will be supplied with water through a branch to 
the street main, eight inches in diameter, forming a portion of 
the body of the hydrant. No part of the permanent portion of 
it will be above the surface of the sidewalk, to make an ob- 
struction there, but, for use, a movable head, or chuck, one of 
which will be carried by each hose-company and one with each 
engine, will be attached to it, making in effect a post-hydrant, 
for the time being, capable of supplying four lines of hose with 
separate gates for shutting off each at pleasure. 
One of these hydrants is now nearly completed for trial, and 
it will be thoroughly tested in every way, so that any necessary 
changes may be made in order to have it as nearly perfect as 
possible before being adopted on the work. 
Many of the tools necessary for its manufacture have been 
made, as they were almost indispensable even for the first one, 
and will be worth their entire cost to any one who is success- CHIEF ENGINEER'S REPORT. 
27 
ful in competing for the contract to furnish the works with 
such number of hydrants as you may think best to call for. 
Some, at least, of those who are expected to bid for the work, 
have ample facilities for making all that will be required, in 
good season for use. 
While making the underground examinations in the basin 
at the pumping station, we found a peculiar material lying at 
varying depths below the surface in a large bed on the west- 
erly side of our proposed excavation. On being poured from 
the bucket in which the material was brought up, the water, 
coming with it, carried upon its surface what seemed to be an 
oily substance, with quite bright and variegated colors. The 
material is formed of very fine particles, nearly black, and 
when dry it is compact and impervious, but on being acted 
upon and diluted by water it runs somewhat like oil, and 
when the eight-inch pipe used in sinking the artesian wells 
was left over night in it, the surface of the material would, in 
the morning, be found several feet higher in the pipe than it 
was the night before. 
Though its depth below the surface, and its position in 
reference to our proposed excavation, is such as to give us no 
great fear of trouble from it, yet it may be that water flowing 
over its surface will afterwards reach the basin and mingle 
with the waters supplied to the city. In view of this possi- 
bility, I sent to Professor Appleton two samples of the mate- 
rial, and one sample of a mixture of the material with water, 
as drawn from one of the wells which was sunk into it, with 
the request that he would ascertain whether any injurious 
matters were contained in, or accompanied, the specimens. He 
found no reason to think that any harm could come to the 
water from a mixture of this material, even if that should 
take place to a much greater extent than seems possible, and 
the fact that neighboring wells are sunk in it, and have their 
visible supply of water held entirely in the material, without 
causing any trouble, except that the water is hard and slight- 
ly brackish, sustains this view. 28 
CITt OF PllOVIDENCF. 
I have appended Professor Appleton's written report in re- 
gard to this subject. 
Examinations are now being made by Professor Appleton 
to ascertain the action of the Pawtuxet water on various kinds 
of pipes used, or proposed to be used, for service pipes. This is 
being done in accordance with your vote authorizing such 
experiments to be made on the Pawtuxet water, and on water 
supplied to other cities. 
It is proposed, also, to send a sample of the water to Pro- 
fessor Chandler, of New York, whose experience in such mat- 
ters is well known, with the request that he will make such 
tests as he thinks may be useful, in regard to its action on 
pipes. 
It is understood to be your wish that great care be exer- 
cised in gaining a knowledge of every essential element to a 
right decision in regard to the kind of service pipes to be 
used on these' works, as the question is a very important one, 
and should be decided independently for every separate water 
supply, on account of the great difference which is known to 
exist between different waters in their action on metals. 
Your quarterly reportshave given information in regatd to 
the engineers whom you have appointed as assistants on the 
wrork. I think the city is fortunate in obtaining such good ser- 
vice as has generally been rendered by them, upon which so 
much of the success and good character of the work depends. 
I am your obedient servant, 
J. HERBERT SHEDD, 
Chief Engineer. CHIEF ENGINEERS REPORT. 
29 
Brown University Laboratory 7 
Providence, Jan. 28, 1870.' j 
J. Herbert Shedd, Esq., 
Chief Engineer of Water Works. 
Dear Sir:-I received from you, Kov. 30th, 1869, two samples of soil 
or earth for chemical examination. They were marked respectively 
A and B. 
Sample A. 
Contained of moisture, - ■ - * 6.28 per cent. 
of matter soluble in water, - * .15 " " 
made up of } solublc organic ami volatile, - .06 " " 
C soluble mineral matters, - - .09 " " 
Sample B. 
Contained of moisture, - - 5.00 per cent. 
of matter soluble in water, - - .25 " « 
made up of 1 soluble organic and volatile matter, .16 " " 
1 soluble mineral " .09 " " 
As the most important point with respect to these soils was the action 
of water upon them, the thing to be determined was the amount of 
soluble matter in them, that is, the amount of matter that would be dis- 
solved by the action of water. 
It will be seen from the statement above, that in each case this amount 
was extremely small-so small as in my opinion to give no ground for 
fear of contamination of water from this source. 
These soils were further examined by aid of the microscope. By 
this means they appeared to consist of two parts:- 
1. A tine part, of no characteristic appearance. 
2. A coarse part, which seemed to consist of quartz and fragments of 
coal. 
Dec. 18th, I860, 1 received from you a sample of water for analysis. 
It was from the same neighborhood as the soil above mentioned and 
was very turbid from the presence of a large amount of mineral 
matter. 
The total amount of matters, suspended and dissolved, was about 393 
grains per American gallon, but of this large amount only 11 grains 
came under the head of organic and volatile matters. Further, these lat- 
ter materials, upon ignition, evolved no flame, showing absence ofanv 
appreciable amount of oily matter. 30 
CITY OF PROVIDENCE. 
A portion of the water was carefully filtered, and the filtrate was 
evaporated for the purpose of determining the amount of matters dis- 
solved, as compared with those merely suspended. 
The results were, 
Total matters,16.6 gr. to Am. gal. 
madeupoft or«:anicandvolatile- ' 12 " 
( mineral, - 15.4 " " 
But these results are a little too high because of the extreme difficulty 
of making the water perfectly clear: nevertheless they are sufficiently 
accurate for the purpose. 
Yours, respectfully, 
JOHN H. APPLETON, 
Professor of Chemistry.