Report of the commissioners appointed under the order of the City Council, August 26, 1844 : to report the best mode and expense of bringing the water of Long Pond into the city of Boston

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City Document. — No. 24,

EEPQ.RT

COMMISSIONERS

APPOINTED UNDER THE ORDER OF THE CITY COUNCIL,

AUGUS T 26, 1844,

REPORT THE BEST MODE AND EXPENSE OF BRINGING

WATER OF LONG POND

INTO THE

CITY OF BOSTON.

BOSTON:
18 44.

JOHN H. EASTBURN, CITY • PRINTER,

No. 18 State Street.

BOSTON, NOYEMBER 9, 1844.

Hon. Martin Brimmer,

Mayor of the City of Boston.

Sir,

The undersigned. Commissioners appointed under the
order of the City Council of August 26, " to report the
best mode and the expense of bringing the water of Long
Pond into the City," having performed the duty assigned
to them under their appointment, have the honor here-
with to communicate to you their report.

Very respectfully, your ob't serv'ts,

P. T. JACKSON, ^

NATHAN HALE, \ Commissioners.

JAMES F. BALDWIN, )

REPORT.

The Commissioners appointed under an order of
the City Council, to " report the best mode, and
the expense of bringing the water of Long Pond
into the City," respectfully submit the following

REPORT:

In determining the best mode of bringing the
water from the proposed source to the City, it seemed
to the Commissioners necessary to consider the pur-
poses for which it is to be used, and the amount of
regular supply required to serve those purposes.
Presuming it to be the desire of the City Council
that the water proposed to be introduced into the
City, shall be sufficient to afford an ample supply to
all the inhabitants, as well for domestic purposes, as
for the protection of the City against fire and for
cleansing the streets, and also for various economical
and manufacturing uses, — particularly the feeding of
steam engines, — it seemed necessary to base their
calculations on some assumed amount of population
to be supplied. It is presumed that since the sub-
ject was last under the consideration of Commission-
ers for a similar investigation, the population of the
City has increased in a ratio of not less than 25 per
cent., and that the present number of inhabitants is

near 110,000. It maybe assumed therefore, that
by the time the proposed introduction of water into
the City can bo accomphshed, the population will
not be far from 125,000. Presuming also that it
will not be the intention of the City Council, to limit
the supply of water to the wants of the existing pop-
ulation, and taking into view the very great and un-
interrupted increase of the City, not only within the
period of seven years already referred to, but for the
last fifty years, in which last period the number of
inhabitants has more than twice doubled, it has been
deemed reasonable to assume, as the basis of our
computation of the amount of daily supply, such a
quantity as will be sufficient for all the public, domes-
tic and manufacturing uses of 250,000 inhabitants ;
or for double the population the City may be expect-
ed to contain, at the date of the completion of the
proposed works.

The next question for consideration is, what meas-
ure of supply shall be assumed, as sufficient to meet
all the wants of this number of inhabitants. On this
point your Commissioners conceive it will be satis-
factory, to adopt the conclusion which was arrived at,
after a careful inquiry into the rate of supply which
had been deemed sufficient in a large number of
other cities, by the Commissioners who were appoint-
ed under an order of the City Council in 1837.
They refer in their report, to the water works of the
City of Philadelphia, as those which afforded as lib-
eral a supply of water, as those of any city within
their knowledge, and they state that the quantity, as
appeared from the official report of the preceding
year, amounted to an average of 2o3< wine gallons, to
each inhabitant within the limits of the distribution.

The Commissioners are the more disposed to adopt
this ratio, as the measure of the proposed supply,
because as far as their knowledge extends, it has
been generally regarded as fully sufficient. At this
ratio, the supply of 250,000 inhabitants will require
7,125,000 gallons of water per day. This is equal
to 950,000 cubic feet, or very nearly a regular flow
of eleven cubic feet a second, through every hour of
the day.

The next point of inquiry which has engaged the
attention of the Commissioners, was to determine
whether the water of Long Pond is sufficient, to
affiDrd a constant supply to this amount. As the
order of the City Council, which defines the duty
of the Commissioners, demands only a report of the
best mode of bringing the water of Long Pond to
the City, without reference to the quantity, it might
at first view appear that the foregoing computations
as to the quantity required, are irrelevant to the ob-
jects of our commission. In our opinion, however,
a definite conception of the quantity required to be
regularly supplied, for meeting the purposes in view,
constitutes an important element, in the calculations
for determining the best mode of bringing the water
to the City. For the same reason, it is important to
determine the extent of the permanent supply of
water, which the pond is capable of affording ; that
the works may be adapted to the purpose of bring-
ing it to the City, without being of greater magni-
tude, and consequently more expensive than is neces-
sary.

This involves an inquiry of great difficulty, arising
from the embarrassments to the exact measurement
of the flow of the water, while it is subject to the

uses of the proprietors of the mills at the outlet, and
more especially from the great variableness of the
flow, in different parts of every season, and also the
great inequality between one season and another.
The Commissioners have given as much attention to
this inquiry, with the aid of a careful engineer, as
the period which has elapsed since their appoint-
ment would allow, and they have also availed them-
selves of the observations and calculations, which
were made by the Commissioners whose report is
above referred to. The unusual drought of the past
season, arising from the small quantity of rain which
fell during a period of two or three months, was fa-
vorable for determining what may be regarded as
the minimum flow of water in any ordinary season.
It may perhaps be proper to regard it as a season of
extraordinary drought, not likely to be often sur-
passed, though it would be unsafe to assume that
even severer droughts may not occur hereafter.

It is perhaps superfluous to remark, that all natural
streams of water vary greatly in the amount of their
discharge, according to the contingency of a dry or
wet season, — the condensation of vapor and the
fall of rain and snow, being the ultimate source of
supply to them all. In our climate, as the summer
and autumn months are usually comparatively dry,
and as a greater amount of water during the heat of
summer escapes by evaporation, the running streams
are in general comparatively low in the autumn, and
a uniform flow of water through the year can be
preserved only by retaining, by artificial means, the
supply afforded in the more rainy parts of the year.
The minor streams and ponds, which serve as feed-
ers to the rivers, are themselves fed in part from

springs proceeding from a greater or less depth in
the earth ; but even these depend for their supply
upon the rain, and gradually diminish, during the
continuance of every dry season — some of them,
hov^^ever, being far more sensibly affected by changes
of the weather than others. Happily for those who
reside under our cUmate, the rain is never so long
withheld, that any of the considerable streams are
entirely dried up, though there is no one which is
not subject to great fluctuation, from the alternations
of wet and dry seasons.

Long Pond is of course not exempt from the effects
of these alternations, though it is not subject to them
in any unusual degree. In the winter and spring, it
receives very large accumulation of water from the
snow and rain, which never fail to fall at those pe-
riods of the year, in greater or less abundance, and
from the small streams and springs which are fed
from those sources. It is thus raised, without the
aid of any artificial dam, to a considerable height
above the level of the outlet. The stream, which at
these periods flows from the pond, is consequently
large, compared with its dimensions after a period of
comparatively dry weather in summer. This stream,
between its outlet and Concord river, is occupied by
two mills, a woolen and carpet factory, belonging to
Mr. WilUam H. Knight. For the supply of these
mills, the water has been usually retained to a certain
height, during a part of the summer, by a dam at the
outlet ; but in every spring, a large surplus is sup-
posed to escape. This dam has been recently in-
creased in height by Mr. Knight, and it is his inten-
tion hereafter, as he has informed the Commissioners,
to retain the water in the spring, at a height of five

8

and a half feet above the outlet, — having acquired a
right to do so, by a purchase of a tract of meadow land,
which will be necessarily flooded by the operation.

This description is necessary, for presenting a dis-
tinct idea of the productiveness and capacity of this
pond. The pond is estimated to cover a surface of
600 acres, but its extent has not been accurately as-
certained by any survey, known to the Commission-
ers. When raised to a height of five and a half feet,
it will cover a still larger surface. The water thus
accumulated will serve to afford, under suitable reg-
ulations, a discharge for several successive months, far
larger than it would afford, in its natural state, during
the dry portion of the year. The pond was drawn
down in part, at an early period of the last spring,
to avoid the damasje which would have been occa-
sioned to the adjoining meadow, which had not then
been purchased by the proprietor of the mills. In
consequence, before the end of summer, all the water
which had been accumulated by artificial means was
exhausted, so that the discharge from the pond had
been reduced, before the first visit of the Commis-
sioners to it, on the 30th of August last, to what
may be denominated its natural summer discharge.
There had been then a very little rain for several
successive weeks, and the stream, in common with
all the neighboring water-courses, was low. The dry
weather continued, with the exception of light rains,
for several succeeding weeks, in which period the sup-
ply of the pond was reduced nearly as low as at any
period of which any information has been obtained.
During this period, a measurement was made under
the direction of the Commissioners, of the period-
ical discharge from the pond. For this measurement,

Mr. Knight afforded every facility, by consenting to
the interruption of the mills, so far as was necessary
for adjusting the apparatus. These measurements
exhibited a discharge, during the thirteen days end-
ing September 24th, equal to an average of 5.1 feet
a second, during the day and night, although the
works were kept running only during the day. But
during the last thirteen days of this period, the sur-
face of the pond was gradually reduced about 0.01
foot per day, or \H inches in the the thirteen days,
which is equal to a draft of 3.2 feet a second. This
shows that during the period mentioned, the quantity of
water running into the pond from streams or springs,
amounted to no more than 1 .9 feet per second, be-
yond the quantity lost by absorption and evapora-
tion. But by carrying this calculation back to the
commencement of the observations on the 30th of
August, we find that the discharge was equal to 5K
feet a second, without any depression of the surface
of the pond, between that date and the 12th of Sep-
tember. By carrying it forward a day and a half, to
the 26th, we find that the pond recovered, in conse-
quence of a rain of twenty-four hours, the full quan-
tity of water which it had lost in the preceding thir-
teen days. The result, therefore, of the measure-
ments, which have been made the present season, is
that the minimum produce of the pond, independent
of what is obtained by reducing the quantity accu-
mulated in it during a period of thirteen days, was
1.9 feet a second, but with the exception of those
thirteen days, the average of any equal or longer
period exceeded five feet a second. The supply since
the 15th of October, and it is presumed through the

10

other parts of the year, has been much larger than
this last amount.

Observations were made under the direction of
the Commissioners appointed in 1837, by which it
appeared that in the autumn of that year, which was
a remarkably dry season, the discharge of the pond,
in the last five days of September, averaged only
1.83 feet per second; and the average of the months
of August, September and October, was 4.93 feet.
The produce of the pond in these three months, after
deducting from the amount of discharge the quantity
obtained by reduction of the pond, was equal to an
average of 3.71 per second, and for four months
5.62 per second.

The above computations of the natural discharge
of the pond, during a season of drought, or during a
a long continued absence of rain, are not to be con-
sidered as affording a measure of the constant sup-
ply, which the pond is capable of affording. The
accumulation of water, in those seasons of the year
which never fail to afford an adequate supply, is a
much surer source on which to rely, than the imme-
diate produce of springs and rivulets, the amount of
which will always fluctuate with the changes of the
weather. According to the observations above re-
ferred to, the discharge of the pond from July 27,
1837, to July 27, 1838, including the dry season of
the former year, was estimated to be equal to an
average of 15.36 feet a second ; and from Novem-
ber 1 837, to November 1 838, embracing a part of the
same year, with a portion of the succeeding year, in
which there was more rain, the discharge amounted
to an average of 21.82 feet a second. These esti-
mates of the discharge from the pond, within the

11

two periods here mentioned, taken in connexion
with such other information as it has been practica-
ble to obtain, relative to the flow of the stream for
some years past, and to the mill power at the out-
let, seem to justify the inference, that the amount of
that flow will, every year, equal an average of at
least twelve feet a second, for the whole year. It
remains to be shown, how the surplus of one por-
tion of the year can be made to supply the deficien-
cy of another, so far as to secure a regular discharge
equal to twelve feet a second, through every part of
the year, — or a certain supply of eleven feet, after a
liberal allowance for leakage and waste.

The pond, as has been observed, forms a natural
reservoir, covering an estimated surface of 600
acres. It is possible that it may fall short of this
estimate, but if we add to it Shakum and Dug Ponds
which communicate with it, and which may be held
in reserve if necessary, there is no doubt that the
three embrace an area of more than 600 acres.

The Commissioners propose, in the mode of con-
structing an aqueduct which they recommend, for
conducting the water to the City, that it shall be so
placed, that when filled to a suflScient height, to af-
ford a supply of eleven feet a second at Corey's Hill,
the surface of water in it shall be seven inches above
the present flume at the outlet, and 3 feet and 10 in-
ches above the bottom of the aqueduct. The pres-
ent dam, as has been stated, was designed to raise
the water to a height of five and a half feet, or four
feet and eleven inches above the proposed water
line in the aqueduct ; and the proprietor of the wa-
ter has acquired the right to flow all, or nearly all,
the land, below this level. There appears to be no

12

room to doubt, from the facts above stated, that wa-
ter enough will flow into the pond every winter and
spring, to fill it to this height, if it should be neces-
sary, and that if the dam should be closed to this
height, a considerable surplus will flow over it, dur-
ing a portion of every year. There will thus be
held in reserve, with a dam of this elevation, 128,-
602,000 cubic feet of water, to be drawn upon at
pleasure during the dry months of the year, or those
in which the flow into the pond may be less than the
required draft upon it. This quantity will be suflicient
to sustain a continued draft of 12 feet a second for a
period of 1 24 days, or seven feet a second for 2 1 2 days.

It has been seen that the produce of the pond, in-
dependently of any draft upon its accumulated re-
sources, during the past summer, was estimated to
exceed 5 feet a second, with the exception of a short
period, and that in 1837, which was also a dry sea-
son, the produce was computed to be equal to an
average of 5.62 feet during the four dry months.
These facts afford the principal data for calculating
the quantity of water which must be held in reserve
for ensuring a continued supply, and the height to
which the dam must probably be raised for the pur-
pose. Further observations will be necessary for de-
termining the most suitable limit to the height of this
reservoir. A very large reserve may be obtained by
a foot or two less of depth than that assumed above.
If raised to a height of 3^ feet only, the quantity
accumulated will be 91,476,000 cubic feet. This
is adequate to sustaining a draft of 12 feet a second
for 88 days, or to making up a deficiency of 7 feet
a second, for 161 days.

Upon the evidence of these facts and computa-

4*»^

13

tions, the Commissioners are of opinion that al-
though the supply of water, running into the pond
from tributary sources, is liable to be reduced, for
short periods in seasons of extreme drought, to a flow
of less than two cubic feet a second, it may safely be
relied on for producing every year an average of at
least 12 feet; and also for retaining, by means of a
dam and gates at the outlet, such a quantity of wa-
ter, as will ensure a regular supply equal to that
amount, through the whole year. Whether it will be
necessary for this object, to retain the water to the
maximum height to which the present proprietor of the
water proposes to raise it for the supply of his mills,
or whether the object may be attained by means of
a dam of considerable less height, is a question
which may be safely left, to be determined hereafter,
especially as the maximum quantity of water cannot
be required for a number of years to come.

The raising of the pond to the greatest height above
proposed, would probably have little injurious effect
upon the banks, or upon the adjoining lands, with
the exception of the tract of meadow already men-
tioned. It is surrounded, for the most part, with a
gravelly beach, entirely free from all vegetable sub-
stances. In some small part, bordering upon streams
flowing into it, there are collections of mud, which
if it be found necessary for preserving the purity of
the water, may be removed. Should it be found
necessary permanently to flow the meadow, it would
be a question for future consideration whether it
would be expedient to remove the peat, of which
it is formed. Whatever may be the height to which
it may be found expedient to raise the surface
of the pond, there can be no difficulty in surround-

14

ing it with a well defined margin, by excavating the
parts imperfectly flowed, so that the part covered
with water shall be permanently covered, and vege-
tation prevented. The injurious effects upon the wa-
ter, from the decay of vegetable matter, in conse-
quence of the flowing of an increased surface, would
be but temporary, and all inconveniences from this
source, may be obviated by raising the pond at once,
in anticipation of the period of the completion of the
works.

Having from the foregoing considerations adopt-
ed the conclusion, that on a liberal estimate of the
probable wants of the City, a supply of water of not
less than 7,000,000 gallons per day ought to be pro-
vided, and that Long Pond may be safely relied up-
on to produce a constant supply to this extent, with
as great a degree of certainty as calculations of this
nature will admit of, it remains next to consider the
best mode of introducing this water into the City,
and of placing it at such an elevation, that it may be
advantageously distributed throughout all parts of
the City, for the purposes for which it is designed.

Before determining upon the character and di-
mensions of the work which should be recommended
for this object, two of the Commissioners visited
New York for the purpose of examining the recently
erected Croton Water Works, for the supply of that
City. By the kind attention and assistance of Hon.
James Harper, the Mayor of the City, and of James
A. Coffin, Esq., President of the Board of Water
Commissioners, and also of Horatio Allen, Peter
Hastie, and E. French, Esqrs., Engineers, the two
latter resident Engineers at the City, and at Sing
Sing, they were aftbrded the fullest opportunity for
examining every part of this magnificent work, which

15

the time they could devote to the inquiry admitted ;
and all their inquiries in regard to the principles of
the work, the method of conducting it, the choice of
materials, and the cost of the various parts of it, were
freely and most satisfactorily answered. The result
of their examination, while it has deeply impressed
them with the skill with which that work has been
conducted, and particularly with its strength and ap-
parent durability, has satisfied them that the leading
principles on which it is constructed are well adapt-
ed to the object proposed here. The Croton Water
Works are of much greater magnitude, and had
much greater obstacles to encounter, than those
which are proposed for the use of this City. They
are adequate to the supply of a million and a half of
inhabitants ; — the aqueduct is of more than double
the length of that proposed by us, — and it traverses a
very uneven and rocky country, in which frequent
tunnelling through extensive ledges of rock and high
embankments were necessary. For retaining the
water of Croton river, and forming a reservoir five
miles in length, covering an area of 400 acres, a
part of which is 55 feet deep, a dam was required to
be erected, of 40 feet in height above low water in
the river : an aqueduct bridge has been built over
the Sing Sing Kill, more than 70 feet in height, and
supported by an arch of hydraulic stone masonry, of
88 feet span ; a much larger bridge yet unfinished,
but rapidly advancing, is to be erected over Harlem
river, 1450 feet in length, on 8 arches of 100 feet in
height, and 80 feet span, and 6 arches of 50 feet
span, — the top of the parapets to be 114 feet above
the ordinary high water line of the river, and 149
feet above the lowest foundation of the piers. There

16

are also two very capacious reservoirs in the City, of
the most thorough construction, one of a capacity of
20,000,000 of imperial gallons, and the other of
150,000,000. All these works are of massive ma-
sonry, of superior workmanship, exhibiting great ar-
chitectural skill, and consequently of great cost.
The water is conveyed from the Croton dam to
Harlem river, through an uninterrupted conduit of
hydraulic brick and stone masonry, 7 feet 5 inches
in width, and 8 feet 5^4 inches in its greatest height.
The aqueduct is laid on a bed of concrete, formed of
hydrauhc cement, sand and broken stone ; it is lined
throughout with brick laid in cement, the covering
consists of an arch of the same materials, and the
sides are supported by walls of stone masonry laid
in cement.

The works proposed, for bringing the water of
Lond Pond to this City, will require no construc-
tion bearing any comparison for magnitude or cost,
with those above enumerated. The Commissioners
recommend the construction of an aqueduct, from
Long Pond to a reservoir, of sufficient capacity to
contain a day's supply, to be formed on Corey's Hill
in Brookline, — a distance of about sixteen miles.
They propose that the aqueduct shall be of brick,
laid in hydraulic cement, of an oval form, five feet
in width, and six feet four inches in height, in the
interior, and broader in the lower section than in the
upper. They recommend this form of the structure,
as well adapted to give it strength, and these dimen-
sions, as sufficient to affi)rd sufficient capacity, and
also to admit of its being easily entered for the pur-
pose of examination and repair, should it become
necessary. They propose that the brick work shall

17

be eight inches in thickness, and that the whole
structure shall be covered with an embankment of
earth, four feet in depth, in every part. They pro-
pose that the conduit shall be laid with an incli-
nation from a level, of three inches in a mile, —
which inchnation is computed to be sufficient, to
admit of the flow of the proposed supply of water,
viz. 1 1 feet a second, by filling the aqueduct to a
depth of three feet and ten inches ; leaving a space
of two and a half feet in height empty.

The dimensions thus proposed are considerably
larger than those of the aqueduct recommended by
the Commissioners of 1837. The reasons for recom-
mending a work of these greater dimensions are,
that the calculations are based on the supply of a
greater number of inhabitants than those of 1837 ; —
it has been deemed an important object to form a
structure of greater height, to admit of its being
more readily entered for the purpose of examination ;
and it was deemed also desirable to deliver the water
at as great an elevation as is practicable, at the res-
ervoir on Corey's Hill, for the purpose of obtaining
the power of a more satisfactory distribution in all
parts of the City. This increase of the dimensions
of the work adds something to the estimate of the
cost, but the advantages gained by it are believed to
be sufficient, to justify the increase of cost.

A line has been surveyed between the termini
above described, on which it is ascertained that
there is no formidable obstacle to the construction
of the work. There will be several places of deep
cutting, none however exceeding 36 feet in depth,
and several large embankments will be required for
sustaining the level. The heavy excavations will be

18

mostly through earth, consisting apparently in great
part of sand or gravel, of easy excavation, and there
are no indications of rock to any great extent on the
line. No measures however have been taken to as-
certain, by any examinations under ground, the
character of the excavations. There are two val-
leys to be crossed, which are too low to admit of the
Hne of the aqueduct being sustained over them,
without incurring an excessive cost. One of these
is at the crossing of Charles River near Newton
Lower Falls, and the other is near Lime Grove, be-
yond Brighton Village. It is proposed to suspend
the brick aqueduct at the crossing of these valleys,
and to convey the water across them by means of a
double line of iron pipes, each of 30 inches diame-
ter, to be laid near the natural surface of the earth,
and to be covered with earth to a depth of four feet.
The length of the two proposed sections of pipes is
2,470 feet, and it is computed that in consequence
of the diminished area of the section of water pass-
ing through the pipes, compared with that in the
brick aqueduct, there will be a loss of level, at the
two valleys, amounting to about fifteen inches.

It is proposed that the water shall be taken from
the pond at a height, after it is introduced into the
aqueduct, of 124.86 feet above the marsh level; and
allowing about four feet for the inclination of the
aqueduct, and 15 inches for fall at the two valleys
crossed by iron pipes, that the surface of water at
the reservoir on Cory's Hill, when it is filled to its
usual height, shall be 119.61 feet. Corey's Hill is
the nearest point of land to the City, which can be
approached by such an aqueduct, as that above de-
scribed, and which is of sufficient elevation for the

19

site of a reservoir. It is at a distance of about four
miles from the State House. From that reservoir,
the water must be conveyed to the City, and dis-
tributed, by means of iron pipes.

To effect a more satisfactory distribution, and to
insure an unfeiUng supply of water for all emergen-
cies, it is recommended that there shall be three or
four reservoirs of moderate dimensions ; one to be
situated on Beacon Hill,— -another on Fort Hill, —
the third on Dorchester Heights in South Boston, —
and a fourth on Copp's Hill in the North part of the
City, if a suitable site can be obtained for the purpose.
These reservoirs may perhaps be dispensed with, by
adopting pipes of larger dimensions for the introduc-
tion of the water from Corey's Hill ; but it is believ-
ed that the object of maintaining an uninterrupted
delivery of the water, at a high level, will be most
effectually and most economically attained, by their
aid.

It is computed that for the distribution of the pro-
posed quantity, of seven millions of gallons per day,
it will be necessary to lay two iron pipes, of 30 inches
diameter, each, from Corey's Hill to a part of Tre-
mont Street near the Roxbury boundary ; — that a
branch from on€ of them, of perhaps 12 inches diam-
eter, shall be carried from this point, in the most
direct and eligible course, to Dorchester Heights,
for the supply of South Boston • that one of them
shall be continued through Tremont Street to
Boylston Street; that branches shall be carried
thence to the reservoirs on Beacon Hill, Fort Hill,
and Copp's Hill ; — and that such other branches
shall be laid, for the conveyance of water to all parts
of the City, as shall be found, on a careful study of

20

the best system of distribution, to be necessary. It
is proposed that the water should be dchvcred at the
reservoir on Beacon Hill, at the height of 111.61
above the marsh level ; 4.68 feet above the level of
the State House floor; and 60 feet above the foot
of the columns, in the Piazza in front of Tremont
House. The proposed level of the reservoir will be
19.81 feet above the level of the sidewalk, at the
corner of Mount Vernon and Temple Streets, and
34.62 feet above the summit of Somerset Street, op-
posite to Somerset Court.

The most extensive and costly works of stone ma-
sonry, which are proposed in this plan of construc-
tion, are the Beacon Hill reservoir, — an arched pas-
sage way, for carrying the aqueduct over a public
highway in Brighton, — and a structure with two
arches for carrying the iron pipes, with a proper
covering of earth for their protection from frost,
across the Charles River.

This is the general outline of the plan of a work,
which the Commissioners recommend as, in their
opinion, best adapted for bringing the water of the
pond into the City, — and on which they have made
an estimate of cost, exhibited in a tabular statement,
which is presented as a part of this report. This
estimate including an allowance for contingencies,
amounts to ^2,1 18,535 83.

The largest item of the estimate consists of the
sum of ^440,155 for the cost of the proposed brick
structure, from the pond to Corey's Hill, which they
have computed at the rate o( $\6 for each thousand
of brick, laid in hydrauhc cement. It is well known
that the price of bricks, in this market, is extremely
variable, according to the extent of the demand ; and

21

that the wages of mechanics and laborers are subject
to material changes, from year to year, from causes
which cannot be foreseen. It is therefore impossible
to estimate with any degree of certainty, what a
work of this description will cost, in any future year.
It is believed, however, that in the estimate here
given, a sufficient allowance has been made for the
different items, to cover the cost of the work, in any
probable state of prices ; or at least that the proba-
bility that the work may be done at a less cost than
this, is greater, than that it will cost more.

Another item of nearly equal magnitude consists
of the cost of iron pipe, for conducting the water
across the two vallies, and from the reservoir on
Corey's Hill to the reservoir in the City, amounting
to $366,501. This is estimated at the rate of 2J4
cents a pound. A similar remark, to that made
above, may be applied to the cost of this article.
The price of pig iron has varied in England during
the last year, from 375. 6d. to SOs. per ton, and in
this country from 20 to 35 dollars. It is therefore
very difficult to foresee at what price any manufac-
ture of iron may be obtained, at a future day. The
rate of our estimate is higher than it would be neces-
sary to pay, if the pipes were to be contracted for at
the present time. The lead to be used for the joints
is estimated at 4 cents a pound, a price higher than
the average value of the article for two or three
years past.

The quantity of excavation, and embankment, is
computed upon the hue of the survey of 1837, with-
out any allowance for a probable improvement of it,
by further examination. In the absence of any
satisfactory evidence as to the character of the earth

->:>

to be removed, in the deep cuts, the whole excava-
tion and embankment, including tlie embankment for
covering the brick aqueduct, except where it is cov'-
ered by replacing the excavated earth, is estimated
at the price of 17 cents per cubic yard. The tilling
of tlie cuttings, by replacing the excavated earth, is
estimated at 10 cenrs per yard.

In the computation for the cost of distributing the
water in the City, the Commissioners instead of
attemptinii a detailed estimate, founded on a digested
plan of distrilninon. and embracin:: a measurement
of tlie streets, and the assignment of tlie particular
size and extent of pipes in each, have taken the esti-
mate which was made for this object, by the Com-
missioners of 1837. without any deduction from this
part of it, tor the reduced cost of iron and lead, since
that date. — and have added to the amount, an increase
of "2-3 per cent, for the increased population now to
be supplied. This result it vras thought would serve
as an approximate estimate, sutnciently accurate tor
the purpose now in view, and nearly as correct as
could be made at the present time. If it is errone-
ous, it is presumed that it errs on the sate side, by
allowing too large rather than too small a sum.

The amonnt allowed, for the cost of a reserroir on
Beacon Hill, can hardly be called an estimate, as it
was impossible to assume for tlie basis of it. any defi-
nite dimensions, or form of construction, without
knowing what suitable site cou Vtaiued for the

purpose. The sum given in the table, embraces the
amount of the estimate made by the Commissioners
of 1837. for a reservoir wliich should hold 750.000
gallons, together with an additional allowance for an
increased cost of land. It was thought safe to assume.

23

that for this cost, a lot of land suitably situated may
be obtained, and a reservoir may be erected, of per-
haps less lateral extent, but of greater depth, which
will serve the purposes of the aqueduct then pro-
posed.

The only remaining item of the estimate, of suffi-
cient magnitude to require particular remark, is that
which is given for the cost of water rights. The
compensation which will be demanded for the di-
version of the water of Long Pond, from the uses
to which it is now appropriated, to the important
one of supplying the inhabitants of the City with
water for domestic uses, presents perhaps the most
difficult question which has yet been considered.
Jn estimating the water rights, which will be thus
invaded, at ^100,000, the Commissioners would not
be understood as rating their actual value for manu-
facturing purposes, independently of the property
which may be injured by withdrawing the water, at
near so high a price.

The supply of the City with water for the domes-
tic purposes of its inhabitants, it is presumed will be
regarded by the Legislature of the State, as one of
those public objects, which justify the taking of pri-
vate property at a valuation to be determined, when
not adjusted by agreement with the parties, in such
manner as shall be provided by law. For property
taken under such circumstances, the City will expect
to pay, not only a full, but a liberal rate of compen-
sation. Such a rate, according to the estimate which
shall be made of the actual value of the water to its
present owners, they will doubtless be ready to offer.
Were the title to compensation vested in a single
claimant, it might have been more easy to ascertain

24

what price would be demanded for it. In the present
state of ownership, of the water of Concord river, the
estimate of the claims of the several parties, presents
a complicated question.

The exclusive right to the use of the water for
manufacturing purposes, from the outlet of the pond,
to its union with Concord river, as has been stated,
is owned by Mr. Knight of Framingham. From
this point the whole of the water of Concord river,
including that of Long Pond, is held by the proprie-
tors of the Middlesex Canal, for the purpose of feed-
ing the canal, with the exception, however, of a
certain reservation for the use of Billerica Mills.
Whether that corporation has a right to use it for any
other purpose, and in such a manner as to divert it
from the Billerica Mills, or from the other mills on
Concord river below Billerica, is a question which
may be raised, but which it does not belong to the
Commissioners to settle. The surplus of water, be-
yond what the Middlesex Canal is competent to use
or dispose of, belongs to the proprietors of Billerica
Mills, and to those of three other privileges on Con-
cord river.

It is perhaps not important for the present purpose,
to know whether the right of disposing of the water
of this river, for any other use than that of supplying
the canal, belongs to the Middlesex Canal Company or
not, because if they are entitled to compensation for
a diversion of the water, the other claimants are not,
and if they are not entitled to it, the other claimants
probably are.

So far as the value of the water depends upon the
actual quantity, and upon the regularity of the sup-
ply, the explanation which has been given above,

25

will serve to show in what manner, in the opinion of
the Commissioners that quantity must be estimated ;
and also such data for the estimate, as can be at
present obtained. The maximum supply which, in
their opinion, can be held in reserve by artificial
means, for regular and permanent use, is computed
not far to exceed the quantity already named, of
twelve feet a second. It might probably be increased
somewhat beyond this amount, but with more or less
hazard of a failure, in the constancy of the supply.
The statements above given also show, that the mini-
mum supply, in periods of drought, without the aid of
improvements yet to be made, and which when made,
must be subject to the control and pleasure of the
proprietor of the falls at the outlet, is less than two
feet a second, and that sometimes during several
successive months, it does not exceed five feet a
second.

The height through which this water falls, at the
two mills of Mr. Knight, as measured by our Engin-
eer, is 12.89 feet. The damage which would be
occasioned by the taking away of a water power,
created by a fall over such a height, of the quantity
of water here described, is not to be estimated merely
by the amount of power produced, independently of
the value of existing works, of which it has become
a necessary appendant. The buildings and machine-
ry would be rendered comparatively useless, if de-
prived of the water power, unless a substitute of
some other power, were provided in its place. The
most obvious mode of computing the value of the
water power, in this case, would therefore be, to
compute the amount of capital which would be re-
quired to provide an equivalent in steam power, and

26

afford a sufficient income to maintain it in perma-
nent operation. In this mode, it is evident, a full
equivalent for the water power could be provided,
by the substitute of steam power. In addition how-
ever to the loss of the water power, he would sus-
tain an injury from the taking away of the water re-
quired by him in a running stream, for the washing
of wool, used in the manufacture carried on by him.
The only mode therefore in which he could be ade-
quately compensated for being deprived of the water
would probably be, to pay him such a sum of money,
as would be equivalent to the purchase of another
water power, and the removal to it of his buildings
and machinery, or perhaps the erection of new build-
ings with a proper allowance for the value of the old
for other uses.

The proper estimate of the damage to the Canal
Company, must depend upon the question whether
the water is likely to be actually wanted for the pur-
pose of sustaining the navigation of the canal. If it
is not wanted for this purpose, it is not apparent in
what way the company would sustain an injury, un-
less they have a right to appropriate it to other uses.
If it is wanted by them for the purpose of feeding
the canal, the most suitable mode of estimating the
damage would probably be, to ascertain the cost of
providing a substitute, for such quantity of water as
the canal would be deprived of, during the seasons
in which they would suffer from a deficiency, by an
equal quantity to be held in reserve for that use, in
an artificial reservoir, to be formed in the vicinity of
Concord river, or on some of its tributary streams.
Such a supply it is believed might be provided for,
at a moderate cost.

27

Should it be decided that the Canal Company has
an unlimited right to dispose of the water of Con-
cord river, including that of Long Pond, for manu- .
facturing purposes, or should it be abandoned by
them, and in consequence become the property of
the owners of the mill privileges, from the canal to
the mouth of Concord river, there seems to be but
one rule by which to estimate the proper value of
the power which can accrue from it, at the several
falls over which it flows. The height of the several
falls is ascertained to be 11.11 feet at the BilL.ica
Mills; 25.31 at Whipple's Mills; 8.39 at the Massa-
soit Mills, and II. 21 at the Middlesex Mills.

By a rule which has been adopted by the proprie-
tors of the Locks and Canals at Lowell, for comput-
ing the amount of mill power, 25 feet of water per
second, on a fall of 30 feet, is assumed to be a
mill power ; and if the fall be less than 30 feet, the
quantity of water to be increased in proportion to
the diminution of fall ; one foot in height to be de-
ducted in all cases for loss of head, and not to be
included in the computation of the proportion. The
highest price at which such a mill power has been
sold at Lowell, is ^^ 14,336, and this is regarded as a
high price for water power. If then a water power,
measured at 25 feet a second falling 36 feet, is worth
;^ 14,336, what is the value of a power arising from
12 feet of water a second, upon falls of 11, 25, 8,
and 1 1 feet respectively ? It is not intended to in-
timate, that these mathematical proportions will in-
dicate the exact value of the water in question, to
these mill privileges, but they show the principle by
which the amount of power may be computed, and
its value estimated, for the purpose of comparison

28

with the estimate, which has been put on proportion-
ate amounts of water power, in other situations.

The computations and estimates, in this report,
are based chiefly on the surveys which were made,
under direction of the Commissioners of 1837.
Some additional surveys have been made for obtain-
ing such further information as was deemed neces-
sary, particularly a revision of the level of the whole
line, and the determination of certain other levels.
For the purpose of indicating the route recommended
in this report, and of explaining the form and dimen-
sions of the proposed aqueduct, the Commissioners
refer to the engraved plan which accompanied the
report of 1 837, impressions of which have been pre-
pared, with some alterations, and with the addition of
a section of the proposed aqueduct. The profile,
exhibited on this plan does not correspond exactly
with that of the work recommended, but it may aid
in rendering the description given in this report more
intelligible.

Which is respectfully submitted.

P. T. JACKSON, j)

NATHAN HALE, > Commissioners.

JAMES F. BALDWIN, )

Boston, November 9, 1844.

ESTIMATE

Of the cost of an Aqueduct for conveying the water
of Long Pond, lying in the towns of Framingham,
Natick and Wayland, to Boston, and for distributing
the same through the City, by a Conduit of brick
masonry, of an oval shape, 5 by 6.33 feet diame-
ter, and by iron pipes, with necessary Reservoirs,
&c. &c.

1844. ^°"'- ^^'•

Nov. Guard Gates, Building, &c. at Long

Pond, 6,000 00

Brick Conduit from Long Pond to Co-
rey's Hill, in Brookline, 84,423 f.=:15
miles 5228 feet, or 15.9893 miles, in-
cluding 1624 feet along side of Reser-
voir, and excluding two pipe sections
of 2470 feet; say 16 miles.

1,719,358 bricks to a mile, laid in hydrau-
lic cement, 8 inches thick. 1,719,358
by 16 miles=27,509,728a $16perm= 440,155 65

For forming bottom for laying brick and

for puddling where necessary, say 10,000 00

Two Pipes, each for Charles River and
Brighton valleys, both equal to 2692 f.
including slopes and laps, and being
double lines=5384 feet. Pipes 30
inches diameter . . . . 51,862 22

Excavation and embankment from Long
Pond to Reservoir on Corey's Hill, in-
cluding earth and rock excavations
and back-filling over brick work and
valley pipes, 180,674 00

Bridges and culverts from Long Pond to

Corey's Hill, 29,785 00

Reservoir on Corey's Hill, 1624 f. long

120 f. wide, 10 deep, - - - 30,715 00

Amount carried forward, ... 749,191 87

30

Dolls. Cts.

1844.

Amount brought foricard, ..... 749,191 87

Two 30 inch pipes from Reservoir on

Corey's Hill to Tremont road, 10,810 f.
Excavation and back-filling, 8,911 95
Bridge across Creek, - 4,507 60

Double line of 30 inch pipes

laid, .... 219,435 60

232,855 15

One 30 inch main pipe, from Tremont

road to Boylston street, 9614 feet,

biidge and earth work, - - - 102,127 46
One 20 inch pipe from Boylston street to

Mount Vernon street, 2310 feet, 11,998 50

One 12 inch pipe from Tremont road to

South Boston Reservoir, say 12,000 ft. 28,701 69

3 Waste Weirs with Ventilators, - 3,000 00

4 Intermediate Ventilators, - - - 1,000 00
Pipes and stop-cocks for drawing off wa-
ter in the 2 valleys, - - - - 700 00

Waste or discharging pipes and stop-
cocks at Corey's Hill, - - - 500 00

Branch pipes with gates or stop-cocks for
letting water into and from Reservoir
on Corey's Hill, .... 1,500 00

Damages for land to be taken around
Long Pond and for the line of Aqueduct
and for Reservoir on Corey's Hill ;
also for line of pipes to Boston and
South Boston, 21,600 00

Water rights, 100,000 00 503,982 80

DISTRIBUTION.

1,253,174 67

Reservoir on Beacon Hill or Mount Ver-
non, 77,339 00

Ditto on Fort Hill, - - - - 6,224 00
Ditto at South Boston, - - 10,000 00

Mains and service pipes for distributing
water through the City, per estimate
of 1838, - - - 463,363 00

To which, add 25 per cent.

for increase of population, 115,841 00 579,204 00 672,767 00

1,925,941 67

Agents and Engineers, Clerks, Office
Rent, and Contingencies, 10 per cent, - - 192,594 16

$2,118,535 83

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BOSTON PUBLIC LIBRARY

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