ANNUAL REPORT 
OF THE 
CHIEF ENGINEER AND GENERAL SUPERINTENDENT 
OF THE 
WASHINGTON AQUEDUCT. 
Department of the Interior, 
Office of the Washington Aqueduct, 
Washington, D. C., October 1, 1864. 
Sir: In conformity with the "regulations for the government of persons 
employed upon the Washington aqueduct," I have the honor to submit the 
following annual report of operations upon the Washington aqueduct during the 
past year. 
I.-CONDITION OF THE WORK. 
Since the date of the last annual report the portions of the conduit then un- 
finished have been completed. At the Great Falls a temporary dam, composed of 
cribs filled with stones and puddled on the upper side, was thrown across a portion 
of the Maryland channel of the Potomac, which raised the water sufficiently to 
give a depth of two and a half feet in the conduit and a daily supply of about 
fifteen million gallons at the lowest stage of the river. 
On the 3d of December, 18(>3, the water from the Potomac was first introduced 
into the conduit, and on the 5th it was allowed to flow into the receiving 
reservoir. 
On December 15 it was shut off to complete the pointing of a portion of the 
conduit; on January 14 it was again introduced, and the reservoir was fed 
from the river until February 24, when several leaks were discovered at 
Cabin John bridge, and on the high embankments between that point and the 
reservoir, which would endanger the further use of the conduit. The balance of 
appropriation then on hand not being sufficient to warrant any expenditure on 
repairs, the water from the Potomac was again shut off, and the supply for the 
city was drawn entirely from the receiving reservoir. 
At the time the leaks were discovered there was from seven to eight feet of 
water in the conduit. Examination showed that the ring had cracked longitu- 
dinally at top and bottom, owing, probably, to the insufficient depth of the earth 
covering. 
After the passage of the appropriation bill, in July, the leaks were repaired, 
and the lower half of the conduit through Cabin John bridge was thoroughly 
plastered. Since these repairs no leakage has occurred. It is probable, however, 
that if the conduit was filled again to the same depth as when the leaks occurred, 
the same result would ensue. For this reason the water in the receiving reservoir 
has been kept at a low level since the 29th of July, when the supply from the 
Potomac was resumed. 
The consumption of water in the city during the dry season was from seven 
to ten million gallons per day. 2 
The spring rains raised the water in the receiving reservoir to the height of the 
dam built across the waste channel in 1863. Between the first of June, when the 
drought began, and the first of August, when the supply from the Potomac began, 
the reservoir was lowered thirteen feet, and had not the conduit repairs been 
completed just at the time they were the supply to the city would have failed. 
During the whole of the winter, and for more than a month after the cessation 
of the rains, the water was exceedingly turbid, but during the drought in June 
and July the sediment was gradually precipitated, and the water is now very 
pure. 
Cabin John bridge has been completed, with the exception of the coping, 
and the scaffolding taken down; no work is now being done on it or any of the 
other unfinished bridges. 
The work on the distributing reservoir at Drovers' Rest was prosecuted until 
about one-third of the slope facings in the western division was laid, when it 
was stopped by the cold weather. The work was resumed in the spring, and 
an expenditure of 88,356 made upon it before the adjournment of Congress, 
when, there being no appropriation available for it, it was again suspended. 
It is very important that at least one section of the distributing reservoir 
should be completed so as to hold a supply of water in case of accident, or when 
the Potomac is rendered muddy by freshets. 
The pipe line is in good condition. The pumping engine in Rock Creek 
bridge is taxed to its utmost capacity, but continues to work well. Twice 
during the year it has been necessary to stop it for slight repairs. A small 
expenditure on the high service reservoir has rendered it available for storage in 
case of a heavy draught caused by fires. 
Congress having made an appropriation on July 2 for the construction of 
the solid masonry dam across the Maryland channel of the Potomac near the 
Great Falls, and for constructing the conduit around the receiving reservoir, 
proposals were invited by advertisement for the construction of these works, 
and were publicly opened on July 25. 
Nine proposals were received for the dam, of which one was withdrawn 
before the award was made. The contract was awarded to James McDonald, 
he being the lowest bidder; he declined to enter into contract, however, and it 
was therefore awarded to the next lowest bidders, Messrs. Dunbar, Sherrill and 
Bangs, with whom a contract was concluded on July 30, and they immediately 
entered upon the work. Great difficulty has been experienced in obtaining 
laborers, owing to the high prices paid for substitutes to enter the army, and 
the fear of incursions from guerilla parties, but considerable progress has been 
made, and there is every prospect of the completion of the dam during the 
summer of 1865. 
For the construction of the conduit around the receiving reservoir six proposals 
were received, and, under your direction, a contract was entered into at the 
lowest prices offered, with Messrs. Dunbar, Sherrill and Bangs, in consideration 
of their having a large amount of tools, shanties, and other fixtures on hand 
with which to commence and carry on the work, and which would otherwise be 
sacrificed to a great extent by reason of the suspension of the other work upon 
which they had been engaged. 
The difficulty of obtaining laborers has somewhat retarded this work also, 
but it is expected that the conduit will be completed within the time specified 
in the contract. 
Copies of these contracts, together with the accompanying specifications, will 
be found annexed to this report. The prices named are considered very reason- 
able, and much lower than those now paid for similar kinds of work in other 
places. Owing, however, to the increased price of labor and materials during 
the past year, they are somewhat higher than the prices assumed in computing 
the cost of these items in the preliminary estimate which was submitted in the 3 
last annual report from this office. The increase in the cost of the dam will be 
about $2,130, and in the cost of the conduit around the receiving reservoir about 
$8,522. 
The question of land damages and water rights at the Great Falls still remains 
unsettled, no action having been taken upon it since the last annual report. 
The masonry at the head of the conduit, and the gate houses at the Great 
Falls and the reservoirs, still remains in an unfinished state. The exposure of 
these structures to the weather in this state is necessarily injurious to them, 
but, with the limited funds at disposal, it has not been considered expedient to 
expend any money except where it was absolutely essential to the completion 
of works required for the supply of the city. 
II.-FINANCIAL CONDITION. 
The following statement shows the amounts appropriated by Congress and 
expended during each year since the beginning of the work : 
Appropriation. 
Expenditure. 
Year ending September 30, 1852 
$5, 000 
$5, 000 00 
Year ending September 30,1853 
100, 000 
14,986 70 
Year ending September 30, 1854 
83,620 41 
Year ending September 30, 1855 
250, 000 
103,602 36 
Year ending September 30, 1856 ...... 
250, 000 
153,156 08 
Year ending September 30, 1857 
1, 000, 000 
220,209 19 
Year ending September 30, 1858 
800, 000 
1, 182, 292 81 
Year ending September 30, 1859 
642, 130 40 
Year ending September 30,1860 
500,000 
24, 725 37 
Year ending September 30,1861 
Year ending September 30, 1862 
260,325 01 
Year ending September 30,1863 
137,622 64 
Year ending September 30,1864 
150, 000 
135,670 63 
Totals 
3, 055, 000 
2, 963, 341 60 
Which leaves a balance of appropriation unexpended up to 
the present time equal to 91,658 40 
The amount of appropriation on hand October 1, 1863, was.. $77, 329 03 
To which was added the proceeds of certain property transferred 
to the War and Navy Departments during the years 1861 
and 1862 3,444 85 
Making total amount on hand 80, 773 88 
To which should now be added amount received from sales of 
wood, stone, timber, machinery, tools, and fixtures during the 
past year 10,697 75 
Amount of appropriation July 2, 1864 150, 000 00 
Total 241, 471 63 
The amount expended during the last year is 135, 670 63 
Balance on hand October 1, 1864 105, 801 00 4 
Estimated cost of completing the Washington aqueduct in accordance with the 
plans recommended in the last annual report, and the supplemental report, 
dated February 22, 1864, (see Senate Mis. Doc. No. 83, Thirty-eighth 
Congress, 1st session.J 
HI.-COST OF COMPLETION. 
Potomac dam $48, 435 00 
Feeder masonry 1,415 00 
Gate-house at Great Falls 3, 480 00 
Bridges 24, 000 00 
Gate-houses and pipe-vaults at distributing reservoir 9,240 00 
High service reservoir, Georgetown 8, 000 00 
Connecting conduit at receiving reservoir 89,311 00 
Distributing reservoir 325, 878 00 
Ventilators'. 2,800 00 
Fencing 20,000 00 
Engineering superintendence and repairs. 30,000 00 
Land and law expenses 5, 000 00 
567,559 00 
Add 10 per cent, for contingencies 56, 755 90 
Total amount 624, 314 90 
Deduct balance on hand October 1, 1864 105, SOI 00 
Appropriation required to complete 518, 513 90 
No provision is made in the foregoing estimate for the settlement of the land 
question at Great Falls, nor for the completion of the Potomac dam to its full 
height entirely across the river. 
Inasmuch as the existing contracts provide for the completion of the Potomac 
dam on or before August 1, 1865, and the conduit around the receiving reservoir 
on or before May 1, 1865, it will be necessary, if the work is to be continued, 
that provision be made in the deficiency bill as follows: 
Required to complete Potomac dam $48, 435 00 
Required to complete connecting conduit 89, 311 00 
Engineering superintendence, repairs, and office expenses.... 20, 000 00 
Total 157,746 00 
Deduct amount on hand 105,801 00 
Deficiency 51,945 00 
If the recommendation to complete the upper section of the distributing reser- 
voir during the present year, for storage and purifying purposes, should meet the 
approval of Congress, the amount required for that purpose will be $160,421, 
and at least $25,000 of the amount should be included in the deficiency bill, in 
order to commence the work as early as the 1st of April next. This will make 
the amount to be included in the deficiency bill $76,945. In order to com- 
plete this section of the distributing reservoir, and provide for other necessary 
expenses connected with the aqueduct during the ensuing year, it will be neces- 
sary that an additional appropriation be made of $150,000. 5 
If the affairs of the country should, in the opinion of Congress, be in a con- 
dition to justify a general resumption of the work on the first of April next, 
with a view to its final completion during the ensuing two years, the additional 
amount in the annual appropriation bill should be $250,000. 
The causes of the increased cost of the Washington aqueduct as provided 
for in the present estimate, over and above the amount originally estimated, are 
fully explained in the last annual report, and the supplemental report of the 22d 
of February, 1864, and it is therefore deemed unnecessary to recapitulate them 
here. 
The departures that have been made from the original plans, and provided for 
in the present estimate, may be briefly stated as follows: 
1. A dam of solid masonry at Great Falls instead of an embankment of broken 
stone. 
2. A connecting conduit around the lower end of the receiving reservoir, so as 
to prevent the adulteration of the Potomac water with the surface drainage col- 
lected in the receiving reservoir. 
3. Slope-wall facing for the inner slopes of the distributing reservoir instead 
of facings of small broken stone. 
4. Raising the dividing bank in the distributing reservoir to the full height of 
the outer banks, and the constructing of a central gate-house therein, so as to 
allow of the independent use of either section for purposes of storage, supply, and 
repairs. 
5. Excavating the bottom of the distributing reservoir to an additional depth 
of thirteen feet, so as to increase the purity of the water, and afford twice the 
amount of storage capacity. 
The first and second changes have been fully indorsed by Congress in the 
bill appropriating $150,000 for the work at the last session, and it is confidently 
believed that the other changes will be approved whenever an appropriation is 
made for the resumption of work upon the distributing reservoir. 
Attention was called in the last* annual report to the importance of providing 
additional facilities for the sewerage and drainage of the city of Washington 
in connexion with the discharge of water from the aqueduct, and also to the 
improvement of the Washington canal and the channel of the Potomac river, so 
as to prevent the accumulation of the filth and excrement of the city in the 
canal which passes through the heart of the city, and upon the flats in the bed 
of the river immediately in front of the city. A resolution was passed during 
the last session of Congress by the House of Representatives providing for an 
examination of this subject under the direction of the Secretary of the Interior, 
but no action was taken upon the subject by the Senate. It is to be hoped that 
some decisive and concurrent action will soon be taken by Congress and the 
authorities of the city upon a subject so vitally important to the capital of the 
nation. 
The annexed map of the line of the aqueduct and of the cities of George- 
town and Washington will serve to illustrate many of the matters referred to in 
this report. 
Respectfully submitted. 
SILAS SEYMOUR, 
Chief Engineer and, General Superintendent. 
Hon. John P. Usher, 
Secretary of the Interior. 
VI. GENERAL REMARKS. 6 
WASHINGTON AQUEDUCT. 
CONTRACT FOR CONSTRUCTION OF MASONRY DAM ACROSS THE MARYLAND CHAN- 
NEL OF THE POTOMAC RIVER. 
Articles of agreement, made and concluded this thirtieth day of July, in the 
year one thousand eight hundred and sixty-four, between Richard Dunbar, 
of Washington city, Charles H. Sherrill, of New York, and Anson Bangs, of 
New York, contractors, of the first part, and Silas Seymour, acting for and in 
behalf of the United States of America, under the authority and subject to 
the approval of the Secretary of the Interior, as chief engineer and general 
superintendent of the Washington aqueduct, of the second part; whereby it 
is covenanted and agreed as follows, to wit: 
The said party of the first part, in consideration of the payments and condi- 
tions hereinafter agreed to be made and performed by the party of the second 
part, hereby covenants and agrees to furnish all the materials and do all the 
work required for the construction of a masonry dam across the Maryland 
channel of the Potomac river near the Great Falls, as the same is described and 
referred to in the specifications hereunto annexed, and which are to be considered 
as forming part of this contract; and, also, in accordance with the directions 
that may from time to time be given by the engineer in charge of the work. 
The work shall be commenced as soon as practicable after the execution of 
these presents, and shall be fully completed, as herein provided, on or before the 
first day of August, eighteen hundred and sixty-five, with the understanding, 
however, that if the progress of the work is delayed or suspended by any act, 
failure, or omission, on the part of the government, or by reason of any direct 
interference therewith growing out of wars, insurrections, or civil commotions, 
no advantage shall be taken of that circumstance by the party of the second 
part to the injury of the party of the first part, but the time shall be extended 
to correspond with such delays as may from their nature be beyond the control 
of the party of the first part. 
Whenever the term engineer, or chief engineer, is used or referred to in 
this contract, or the annexed specifications, in connexion with the proper execu- 
tion of the work, it is understood to apply to the chief engineer, for the time 
being, in charge of the Washington aqueduct; and, also, when said chief engi- 
neer is not personally present, to his assistants and inspectors employed upon 
the work and acting under his directions. 
The work must be commenced at such points, and carried forward at such 
times and seasons, and in such order and rates of progress, as the chief engineer 
may direct, and shall, during its progress, be subjected to his constant super- 
vision and direction; and the whole must be executed in the most substantial 
and workmanlike manner, and to the entire satisfaction of said engineer. 
For the purpose of avoiding all cause of difference or dispute between the 
parties to this agreement relative to its true intent and meaning, and for the 
purpose of adjusting, in an amicable manner, any difference that may arise 
relative thereto, it is hereby mutually understood and agreed by and between 
rhe parties, that the chief engin ter shall determine the amount or quantity of 
the several kinds of work herein contracted to be done and materials furnished, 
(and shall have full power to reject or condemn all work or materials which, in 
his opinion, do not fully conform to the spirit of this contract, and shall also 
decide every question which can or may arise between the parties relative to 
the execution thereof, and his decision shall be final and conclusive. 
Changes in the location of the work, or in the plans and specifications of the 
same, which do not materially affect its cost, shall not be deemed to constitute 
any claim for extra compensation. But if any changes be made which, in the 7 
opinion of the chief engineer, materially increase or diminish the cost or diffi- 
culties of performing the work, it shall be his duty to add to or deduct from the 
contract prices, in proportion to said increase or diminution; and if any work 
be done, or materials furnished, which are not now contemplated or provided for 
in this contract, the said engineer shall allow the contractors such prices for 
the same as he may consider just and equitable. 
If the contractors shall refuse or unreasonably neglect to remedy any im- 
perfection in the materials or workmanship which may be pointed out by the 
engineer, or shall in any manner violate the conditions of this contract, so that, in 
the judgment of the engineer, there shall be just grounds of apprehension that 
the work will not be completed in the manner and in the time specified, (unless 
such delay shall have occurred by reason of causes hereinbefore referred to,) 
then said engineer shall have power, and it shall be his duty, to declare this 
contract forfeited by the contractors; and, in case of such forfeiture, the govern- 
ment may proceed to enter into contract with any other person or persons, or 
may make any other arrangements to complete the work, in the same manner as 
if this contract had never existed. And the government may thereupon retain 
for its own use any reserved percentage or estimates which might, under other 
circumstances, have been due to the contractors, free of any claim thereto by 
the contractors. 
The aforesaid chief engineer shall also have the power, at his option, to em- 
ploy laborers and furnish materials for the said work, whenever, in his opinion, 
the more speedy prosecution thereof will be better attained by such means, or 
the interest of the government better promoted thereby, and to charge the ex- 
penses of the same to the contractor in the monthly or final estimates for said 
work; and the said engineer is further authorized and empowered to require the 
party of the first part to pay all just demands for labor and materials that may 
be incurred by him or his agents in connexion with the prosecution of said work 
and properly chargeable thereto; and for that purpose the said chief engineer 
may retain from the estimates a sufficient amount to cover said demands, and 
apply the same to the payment thereof, in case the contractor refuses to liquidate 
said demands within thirty days after receiving notice from the chief engineer 
that the same have been satisfactorily verified and left with him for collection. 
But all such claims must be placed in the hands of the chief engineer, together 
with proper evidences of their correctness, within thirty days after the date 
when due. 
The contractors shall immediately dismiss from their service any foreman, 
laborer, or other persons, who are insolent, riotous, or disorderly in their con- 
duct, or disobedient to the directions of the engineer, or who, in the opinion of 
the engineer, are unskilful or remiss in the performance of their duty; and no 
person shall be employed upon the work who is not a citizen of the United 
States, and known to be loyal to the government. 
The aforesaid party of the second part, in consideration of the full and faith- 
ful performance, by the parties of the first part, of all the conditions and cove- 
nants hereinbefore set forth to be by them performed and kept, hereby covenants 
and agrees to pay to the said parties of the first part, upon the certificate of the 
chief engineer, as soon after the first day of each month, during the progress of 
the work, as the estimates can be conveniently prepared, for materials delivered 
and labor performed under this contract, at the rates and prices named in the 
following schedule, viz : 
Schedule of prices for work and materials required for constructing a dam of 
solid masonry across the Maryland channel of the Potomac river, near the 
Great Falls. 
For clearing and grubbing the entire work, one thousand and eight hundred 
(1,800) dollars. 8 
For excavation in foundations, two (2) dollars and fifty (50) cents per cubic 
yard. 
For concrete and grout in foundations, eight (8) dollars per cubic yard. 
For foundation masonry, fourteen (14) dollars per cubic yard. 
•For superstructure masonry, fourteen (14) dollars per cubic yard. 
For coping, twenty (20) dollars per cubic yard. 
For wrought iron, in bolts and clamps, fifteen (15) cents per pound. 
For back filling, three (3) dollars and fifty (50) cents per cubic yard. 
For materials, either delivered, manufactured, or ready for delivery and use 
in the work, the engineer will make such an allowance in his monthly estimates 
as, in his opinion, may be fairly proportionate to the value of such materials 
when placed in the work; and when such allowances are made, and the esti- 
mates paid, such materials shall become the property of the government; but 
the contractors shall be held responsible for their safe-keeping and final use in 
the work. 
The engineer will deduct ten per cent, from all monthly estimates; which 
amount shall be retained by the government as part security for the full and faith- 
ful performance of this contract on the part of the contractors. The per centage 
thus retained, together with the final estimate of the chief engineer, covering all the 
work done and materials delivered on the final completion of the work, in accord- 
ance with the conditions of this contract, shall become due and be paid to the 
said party of the first part, their successors or assigns, by the party of the 
second part, within thirty days after the completion of said work. 
It is further understood and agreed by the parties hereto, that this contract, 
and all the provisions thereof, are subject to the laws of Congress heretofore 
passed in relation to government contracts, and more particularly to the joint 
resolution approved April 14, 1852, in which it is "Provided, That nothing here- 
in contained shall be so construed as to authorize any officer of the United States 
to bind the United States by contract beyond the amount appropriated by Con- 
gress, or to sanction any such contract heretofore made." 
It is also understood that the government reserves the right to suspend the 
Work embraced in this contract at any time; and that when the work has been 
faithfully performed by the contractor he will, on such suspension, be paid in 
full for all work done and materials delivered, and that, unless the work is re- 
sumed within one year from the date of said suspension, the contractor will be 
entitled to payment for the necessary fixtures on hand, and to a cancelment of 
the contract, and a full release and satisfaction of himself and his bonds and 
sureties from the further performance thereof. 
It is expressly understood and agreed, that the several stipulations of this con- 
tract shall be performed in such a manner that the party of the first part will 
not be relieved from the immediate charge and responsibility of the work; and 
the same shall not be transferred or assigned, nor any portion of the work em- 
braced therein sub-let to other parties, unless by the written sanction of the 
chief engineer, and approval thereof by the Secretary of the Interior. 
In witness whereof the parties to these presents have hereunto set their hands 
and seals in triplicate, on the day and year first above written. 
RICHARD DUNBAR. [l. s. 
CHAS. H. SHERRILL. l. s. 
ANSON BANGS. Jl. s. 
S. SEYMOUR, [l. s? 
Chief Engineer. 
Subject to the approval of the Secretary of the Interior. 
Approved: 
J. P. USHER, Secretary. 9 
Guarantee. 
Know all men by these presents, that we, Alexander W. Randall, of the State 
of Wisconsin, and Robert C. Murphy, of Washington city, D. C., in considera- 
tion of the premises, and of one dollar to us in hand paid by the United States, 
the receipt whereof is hereby acknowledged, do hereby, severally and jointly, 
covenant and agree with said United States that the above-named Richard Dun- 
bar, Charles H. Sherrill, and Anson Bangs, shall in all things faithfully perform 
all and singular the covenants and conditions in the foregoing contract set forth 
to be by them performed and kept. 
Witness our hands and seals this thirtieth day of July, 1864. 
ALEX. W. RANDALL. [l. s.l 
R. C. MURPHY. [l. s.j 
In presence of- 
Jas. H. Marr, Jr. 
J. J. R. Croes. 
Specifications for constructing a dam of solid masonry across the Maryland 
channel of the Potomac river near the Great Falls. 
Clearing and grubbing.-The ground set apart for the work and embraced 
within the boundary lines as fixed by the engineer will be thoroughly cleared 
of all trees, stumps, logs, and bushes, and the whole, or such portions thereof 
as the engineer may direct, will be entirely removed or destroyed. 
Preparing foundations.-The foundation of the dam will, whenever practi- 
cable, rest upon sound, imperishable, native rock. All earth, boulders, detached 
rock, and such portions of the present rock surface as are unfit for the founda- 
tions, will be removed as directed by the engineer, so as to secure a firm, even, 
and durable bearing for the foundation masonry. 
Whenever required by the engineer, the irregularities and fissures in the na- 
tive rock will be thoroughly filled with concrete or grout, so as to prevent the 
passage of water, and afford a proper and uniform bearing for the masonry. 
Foundation masonry.-The masonry in the foundation will extend from the 
rock foundation, as above described and provided for, up to the level of low- 
water mark in the river, at the point of crossing. It will be built of undressed, 
heavy, and well-shaped stone, properly bonded, and laid upon their broadest 
natural beds, in full mortar or grout as the engineer may direct, so as to be 
perfectly tight and impervious to water, and also to sustain the superincumbent 
weight of the superstructure. The lower face will have a slope, either in steps 
or batter, as the engineer may direct, of two feet base to one foot rise, and the 
upper face will have a slope, in steps, of one to one. The steps must, in all 
cases, extend well back into the wall. The upper course, upon which the su- 
perstructure of the dam is to rest, will be composed of large, flat stones, not less 
than one foot in thickness, which must extend at least two feet under the super- 
structure masonry, and project outwardly one foot along each side of the base 
of the superstructure. The top of the foundation masonry must be brought to 
a firm, level, and uniform surface before the superstructure masonry is com- 
menced. 
Superstructure masonry.-The lower or front face of the superstructure will 
be vertical; the rear face will batter in the ratio of four inches to the vertical 
foot, and the top will be seven feet thick, measured horizontally on the line of 
the upper front angle. The bed for the coping will slope in the ratio of one 
inch to the foot from front to rear. The work will be of the best quality of 
rubble cement masonry, up to the bed of the coping. The coping will be of 
cut stone. 10 
Rubble work will be composed of sound, durable* and well-shaped stone, 
laid alternately, with headers and stretchers, in full mortar or grout, as the engi- 
neer may direct, throughout the work. The front faces, beds, and joints to be 
rough-dressed with the hammer, so that there will be no projections of more 
than one inch outside of the true face line of the work, and so as not to admit 
of more than one-half inch thickness of mortar in the beds and joints. No 
stone less than eight inches thick will be allowed in the front face, and none 
less than six inches thick in the rear face. The upper course must be not less 
than sixteen inches thick in front and eight inches in the rear, and must be 
composed entirely of headers, both in front and rear, interlocking with each 
other at least two feet in the centre of the wall. The upper surface, or bed for 
the coping, must be smoothly dressed to an uniform plane, inclining one inch 
to the foot from front to rear, so as to afford a firm and uniform bearing for the 
coping; an arris of two inches in width, corresponding with the front line of 
the work, will be cut with the chisel along the upper front angle of this course. 
Coping.-The coping will be of Seneca sandstone, or a stone of equally good 
quality, and will be cut to the patterns and drawings furnished by the engineer. 
The front face of the coping will be vertical, and eighteen inches thick, project- 
ing three inches over the front line of the wall. The front and rear upper an- 
gles will be either rounded or bevelled off, as the engineer may direct. The 
lower surface will conform to the slope of the bed prepared upon the underlying 
masonry. The upper surface will be level for a space extending two feet back 
from the front face, and will, from that point, be so dressed as to slope to the 
rear in the ratio of two inches to the foot when laid in place. Each stone must 
have at least three feet width of bed, and must, when practicable, extend en- 
tirely across the wall. When this is not practicable, they will have such length 
of bed as the engineer may direct. The coping will be laid to one-quarter inch 
joints, both vertically and horizontally, and each stone will be bolted to the 
wall below as often as the engineer may direct, with wrought-iron bolts of not 
less than one and a quarter inch in diameter, and of such length as to extend 
through the coping and penetrate the wall below at least one foot, and to be 
secured with a fox-wedge at the bottom and with sulphur and sand cement. 
The coping stone will be fastened together, as often as the engineer may direct, 
with wrought iron clamps, made of one-half by three-quarter inch iron, with 
prongs extending at least six inches into the stone, and properly secured with 
lead. The heads will be countersunk into the stone, so as to be flush with the 
upper surface. 
Back filling.-The rear angle formed by the back face of the dam and the 
bed of the river will be filled with good coarse gravel or broken stone, as the 
engineer may direct, extending from the top of the dam with a uniform slope 
not exceeding three feet horizontal to one foot vertical, until it reaches the bed 
of the river. 
The whole to be executed in the most substantial and workmanlike manner, 
and to the entire satisfaction of the engineer in charge of the work. 
The prices named in the contract will include the furnishing of all the mate- 
rials required for the work as herein specified and provided for, together with 
the labor necessary for putting the same in place, including all coffer-dams, 
pumping, bailing, and draining required in preparing the foundations, and all 
other matters and things necessary to the full and final completion of the work. 
Specifications for cement, sand, mortar, grout, and concrete. 
Cement.-The cement used in the work must be of the best quality of hy- 
draulic cement, equal in character to the Rosendale. It must be fresh, well 
burned and ground, free from foreign substances, and put up in air-tight casks. 
It must also be subject to such tests as the engineer may direct, and the con- 
tractor must keep it entirely protected from the weather until used in the work. 11 
Sand.-The sand used in the work must be clean and sharp, free from loam, 
dust, mica, or other impurities which will hinder it from mixing freely with the 
cement. It must be thoroughly screened and washed when required by the 
engineer. 
Mortar.-All mortar used in the work will be composed of hydraulic cement 
and sand, mixed with water in such proportions as the engineer may direct, 
generally one part of cement to two parts of sand. The materials will always 
be measured under the eye of the inspector, and whilst dry thoroughly mixed 
on a tight, wooden platform; after which a sufficient quantity of clean water 
will be applied to bring it to the proper consistency, and then it will be worked 
with hoes until all the particles have become thoroughly intermixed. The 
quantity so manufactured must not exceed the amount required for immediate 
use; and it must be applied to the work within the proper time for rendering 
the adhesion and solidification most perfect. No mortar will be used in the 
work which has been once set and worked over the second time. 
Grout.-When grout is required in the work it will be composed of the same 
kind and quality of materials, and mixed in the same proportions, as above 
specified for mortar, except that it will be manufactured in a tight box, and, by 
the addition of water, reduced to a proper consistency for running freely through 
the interstices of the masonry, or other substance to which it may be applied, 
until, when fully set, the whole mass becomes perfectly solid and impervious to 
air or water. 
Concrete.-When concrete is used in the work it will be composed generally 
of one part of cement, two of sand, arid five of hard, durable rock, broken to 
pass through a two-inch ring. These proportions will be varied at the discretion 
of the engineer. The cement and sand will be mixed dry, and reduced to the 
proper consistency with water before the stone are added. The whole mass will 
then be thoroughly worked with hoes or shovels, and applied to the work im- 
mediately in layers not more than eight inches thick-each layer to be properly 
confined in its place, and rammed until the mortar flushes to the surface-and it 
must become thoroughly solidified before another layer is added. 
CONTRACT FOR CONSTRUCTION OF CONDUIT AROUND THE RECEIVING RESERVOIR. 
Articles of agreement, made and concluded this second day of August, in the 
year one thousand eight hundred and sixty-four, between Richard Dunbar, of 
Washington city, Charles H. Sherrill, of Mew York and Anson Bings, of 
New York, contractors, of the first part, and Silas Seymour, acting for and in 
behalf of the United States of America, under the authority and subject to 
the approval of the Secretary of the Interior, as chief engineer and general 
superintendent of the Washington aqueduct, of the second part; whereby it 
is covenanted and agreed as follows, to wit: 
The said party of the first part, in consideration of the payments and condi- 
tions hereinafter agreed to be made and performed by the party of the second 
part, hereby covenants and agrees to furnish all the materials and do all the 
work necessary for the construction of the conduit and tunnel around the re- 
ceiving reservoir, as the same is described and referred to in the specifications 
hereunto annexed, and which are to be considered as forming part of this con- 
tract; and, also, in accordance with the directions that may from time to time 
be given by the engineer in charge of the work. 
The work shall be commenced as soon as practicable after the execution of 
these presents; and shall be fully completed, as herein provided, on or before 
the first day of May, eighteen hundred and sixty-five, with the understanding, 
however, that if the progress of the work is delayed or suspended by any act, 
failure, cr omission, on the part of the government, or by reason of any direct 12 
interference therewith growing out of wars, insurrections, or civil commotions, 
no advantage shall be taken of that circumstance by the party of the second 
part to the injury of the party of the first part, but the time shall be extended 
to correspond with such delays as may from their nature be beyond the control 
of the party of the first part. 
Whenever the term engineer, or chief engineer, is used or referred to in this 
contract, or the annexed specifications, in connexion with the proper execution 
of the work, it is understood to apply to the chief engineer, for the time being, 
in charge of the Washington aqueduct; and, also, when said chief engineer is 
not personally present, to his assistants and inspectors employed upon the work, 
and acting under his directions. 
The work must be commenced at such points, and carried forward at such 
times and seasons, and in such order and rates of progress, as the chief engineer 
may direct, and shall, during its progress, be subjected to his constant super- 
vision and direction ; and the whole must be executed in the most substantial 
and workmanlike manner, and to the entire satisfaction of said engineer. 
For the purpose of avoiding all cause of difference or dispute between the 
parties to this agreement relative to its true intent and meaning, and for- the 
purpose of adjusting, in an amicable manner, any difference that may arise rela- 
tive thereto, it is hereby mutually understood and agreed by and between the 
parties, that the chief engineer shall determine the amount or quantity < f the 
several kinds of work herein contracted to be done and materials furnished ; and 
shall have full power to reject or condemn all work or materials which, in his 
opinion, do not fully conform to the spirit of this contract; and shall also decide 
every question which can or may arise between the parties relative to the exe- 
cution thereof, and his decision shall be final and conclusive. 
Changes in the location of the work, or in the plans and specifications of the 
same, which do not materially affect its cost, shall not be deemed to constitute 
any claim for extra compensation. But if any changes be made which, in the 
opinion of said chief engineer, materially increase or diminish the cost or diffi- 
culties of performing the work, it shall be his duty to add to or deduct from the 
contract prices, in pi oportion to said increase or diminution ; and if any work 
be done, or materials furnished, which are not now contemplated or provided for 
in this contract, the said engineer shall allow the contractors such prices for the 
same as he may consider just and equitable. 
If the contractors shall refuse or unreasonably neglect to remedy any imper- 
fection in the materials or workmanship which may be pointed out by the engi- 
neer, or shall in any manner violate the conditions of this contract, so that, in 
the judgment of the engineer, there shall be just grounds of apprehension that 
the work will not be completed in the manner and in the time specified, (unless 
such delay shall have occurred by reason of causes hereinbefore referred to,) 
then said engineer shall have power, and it shall be his duty, to declare this 
contract forfeited by the contractors; and, in case of such forfeiture, the govern- 
ment may proceed to enter into contract with any other person or persons, or 
may make any other arrangements to complete the work, in the same manner as 
if this contract had never existed. And the government may thereupon retain 
for its own use any reserved percentage or estimates which might, under other 
circumstances, have been due the contractors, free of any claim thereto by the 
contractors. 
The aforesaid chief engineer shall also have the power, at his option, to em- 
ploy laborers and furnish materials for the said work, whenever, in his opinion, 
the more speedy prosecution thereof will be better attained by such means, or 
the interests of the government better promoted thereby, and to charge the ex- 
penses of the same to the contractor in the monthly or final estimates for said 
work ; and the said engineer is further authorized and empowered to require the 
party of the first part to pay all just demands for labor and materials that may 13 
be incurred by him or his agents in connexion with the prosecution of said work 
and properly chargeable thereto ; and for that purpose the said chief engineer 
may retain from the estimates a sufficient amount to cover said demands, and 
apply the same to the payment thereof, in case the contractor refuses to liquidate 
said demands within thirty days after receiving notice from the chief engineer 
that the same have been satisfactorily verified and left with him for collection. 
But all such claims must be placed in the hands of the chief engineer, together 
with proper evidences of their correctness, within thirty days after the date 
when due. 
The contractors shall immediately dismiss from their service any foreman, 
laborer, or other persons, who are insolent, riotous, or disorderly in their con- 
duct, or disobedient to the directions of the engineer, or who, in the opinion of 
the engineer, are unskilful or remiss in the performance of their duty; and no 
person shall be employed upon the work who is not a citizen of the United 
States, and known to be loyal to the government. 
The aforesaid party of the second part, in consideration of the full and faith- 
ful performance, by the parties of the first part, of all the conditions and cove- 
nants hereinbefore set forth to be by them performed and kept, hereby covenants 
and agrees to pay to the said parties of the first part, upon the certificate of the 
chief engineer, as soon after the first day of each month, during the progress of 
the work, as the estimates can be conveniently prepared, for materials delivered 
and labor performed under this contract, at the rates and prices named in the 
following schedule, viz: 
Schedule of prices for work and materials required for the construction of the 
conduit around the receiving reservoir. 
Clearing and grubbing required for the entire work, five hundred (500) dollars. 
Earth excavation, thirty-five (35) cents per cubic yard. 
Rock excavation, three (3) dollars and fifty (50) cents per cubic yard. 
Tunnel excavation ten (10) dollars per cubic yard. 
Embankment, forty-two (42) cents per cubic yard. 
Retaining wall, six (6) dollars per cubic yard. 
Brick masonry in conduit, sixteen (16) dollars per cubic yard. 
Stone masonry in conduit, ten (10) dollars per cubic yard. 
Concrete and rubble cement masonry in foundations, nine (9) dollars and fifty 
(50) cents per cubic yard. 
For materials, either delivered, manufactured, or ready for delivery and use 
in the work, the engineer will make such an allowance in his monthly estimates 
as, in his opinion, may be fairly proportionate to the value of such materials 
when placed in the work ; and when such allowances are made, and the estimates 
paid, such materials shall become the property of the government, but the con- 
tractors shall be held responsible for their safe-keeping and final use in the work. 
The engineer will deduct ten per cent, from all monthly estimates, which 
amount shall be retained by the government as part security for the full and 
faithful performance of this contract on the part of the contractors. The per- 
centage thus retained, together with the final estimate of the chief engineer, 
covering all the work done and materials delivered on the final completion of 
the work, in accordance with the conditions of this contract, shall bee me due 
and be paid to the said party of the first part, their successors or assigns, by 
the party of the second part, within thirty days after the completion of said 
work. 
It is further understood and agreed by the parties hereto, that this contract, 
and all the provisions thereof, are subject to the laws of Congress heretofore 
passed in relation to government contracts, and more particularly to the joint 
resolution approved April 14,1852, in which it is " Provided, That nothing herein 14 
contained shall be so construed as to authorize any officer of the United States 
to bind the United States by contract beyond the amount appropriated by 
Congress, or to sanction any such contract heretofore made." 
It is also understood that the government reserves the right to suspend the 
work embraced in this contract at any time; and that when the work has been 
faithfully performed by the contractor, he will, on such suspension, be paid in 
full for all work done and materials delivered, and that, unless the work is re- 
sumed within one year from the date of said suspension, the contractor will be 
entitled to payment for the necessary fixtures on hand, and to a cancelment of 
the contract, and a full-release and satisfaction of himself and his bonds and 
sureties from the further performance thereof. 
It is expressly understood and agreed that the several stipulations of this 
contract shall be performed in such a manner that the party of the first part 
will not be relieved from the immediate charge and responsibility of the work; 
and the same shall not be transferred or assigned, nor any portion of the work 
embraced therein sub-let to other parties, unless by the written sanction of the 
chief engineer, and approval thereof by the Secretary of the Interior. 
In witness whereof, the parties to these presents have hereunto set their hands 
and seals, in triplicate, on the day and year first above written. 
RICHARD DUNBAR. [l. s. 
CHARLES H. SHERRILL, [l. s. 
ANSON BANGS. l. s.' 
S. SEYMOUR, [l. s. 
Chief Engineer. 
Subject to the approval of the Secretary of the Interior. 
Approved: J. P. USHER, Secretary. 
Guarantee. 
Know all men by these presents, that we, Alexander W. Randall, of the 
State of Wisconsin, and Robert C. Murphy, of Washington, D. C., in consider- 
ation of the premises, and of one dollar to us in hand paid by the United States, 
the receipt whereof is hereby acknowledged, do hereby, severally and jointly, 
covenant and agree with said United States that the above-named Richard 
Dunbar, Charles H. Sherrill, and Anson Bangs, shall in all things faithfully 
perform all and singular the covenants and conditions in the foregoing contract 
set forth to be by them performed and kept. 
Witness our hands and seals this second day of August, 1864. 
ALEXANDER W. RANDALL. 
R. C. MURPHY. 
In presence of- 
James H. Marr, Jr. 
J. J. R. Croes. 
Specifications fior graduation. 
Clearing and grubbing.-The ground set apart for the work will be thoroughly 
cleared of all timber, stumps, roots, and brushwood, and the same will be either 
destroyed or removed outside the boundary lines as fixed by the engineer. The 
surface of ground forming excavations, and also the ground upon which embank- 
ments are to rest, will be thoroughly stripped of all muck or vegetable matter, 
and the same will be disposed of as directed by the engineer. The price named 
in the contract for this item will include all work of the above character. 
Excavation.-The open excavation for the conduit will generally be fourteen 
feet wide at the centre of the conduit, w-hich is the grade line of the aqueduct. 15 
The slopes will vary from one foot base to from one to four feet rise, at the dis- 
cretion of the engineer, according to the nature of the material. Excavation will 
be divided into three classes, to wit: earth excavation, rock excavation, and 
tunnel excavation. 
Earth excavation will include all material softer than rock, and also all 
detached masses of rock or boulders measuring less than one-half a cubic yard 
in size, whether found in open cuts, the bed of the conduit, benches, foundations, 
borrowing pits, side drains, or in any other manner connected with the work. 
Rock excavation will include all material harder than earth, except detached 
masses and boulders as above described, whether found in open cuts, the bed of 
the conduit, benches, foundations, side drains, approaches to tunnels, or in any 
other manner connected with the work. 
Tunnel excavation will be circular in form, and of eleven feet clear diame- 
ter, and will include all material of whatsoever nature found between the 
extremities of the tunnel. 
The quantity of material in tunnels will be computed by multiplying the net 
area of eleven feet diameter into the length of tunnel. Any material excavated 
outside of these dimensions will be at the expense of the contractor, unless the 
same be directed as a measure of safety or necessity by the engineer. 
The prices named in the contract for the above three classes of excavation 
will include the cost of all pumping, bailing, and draining that may be necessary, 
and the removal of all material to the place designated by the engineer, unless 
the haul should exceed a distance of five hundred feet, in which case an additional 
price of one cent per cubic yard will be allowed for each one hundred feet so 
hauled in excess of five hundred. The prices will also include the depositing of 
any portion of said materials in spoil banks, as the same may be directed by the 
engineer. 
Embankment.-This item will include all labor and expense necessary in the 
proper arrangement and manipulation of such material as may be selected by the 
engineer and deposited from excavations, when used either in the foundations, 
the banks upon which the conduit is to rest, the formation of side slopes, the 
trimming for the bed of the conduit, the covering of the conduit, top and slope 
dressings, ramming, puddling, together with any and all other labor and expenses 
connected with the final disposition of the material and completion of the work, 
as the same may be measured in embankment, which is not properly chargeable 
to the excavation and removal of said material as provided for under the head 
of excavation. 
The banks and side slopes designed for the support of the conduit must be 
composed of material selected by the engineer, and entirely free from perishable 
matter, and must be formed by placing the material in horizontal layers of not 
less than three nor more than six inches in thickness, as the engineer may direct; 
after which it must be rammed with heavy hand-mauls until it has become per- 
fectly solid and incompressible. 
The material upon the top of the conduit, whether in excavations or upon 
embankments, must also be approved by the engineer, and carried up in hori- 
zontal layers not exceeding six inches thick, and properly solidified by carting 
thereon, or the use of rammers, as the engineer may direct. Whenever, in the 
opinion of the engineer, the safety or durability of the work requires that any 
portion of the banks should be puddled instead of rammed, as above described, 
the gjjime shall be done in such manner as the engineer may direct. 
Retaining wall.-Whenever required by the engineer, retaining walls will be 
constructed to support the outer slope of the embankments. These will be built 
of dry rubble masonry, composed of durable, well-shaped stones, laid with alternate 
headers and stretchers in a workmanlike manner, as directed by the engineer. 
The face of the wall will generally batter one foot in four, and the thickness of 16 
the base will generally be equal to one-third the height; but it may vary from 
these particulars in form and dimensions at the discretion of the engineer. 
These walls, when required by the engineer, will extend underneath the 
conduit. 
Specifications for conduit. 
The centre of the conduit is, in all cases, the grade line of the aqueduct. 
The foundation or bed of the conduit in earth-work must be carefully trimmed 
below grade, so as to conform to the outer circumference of the conduit; and in 
rock-work it will be levelled or surfaced up to the same line with concrete or 
rubble masonry, as the engineer may direct. 
The conduit will be circular in form, and nine feet interior diameter. It will 
be constructed of brick or stone, or in parts and sections of each, at the discre- 
tion of the engineer. 
When brick are used they must be of the best quality, full and uniform in 
size, and hard-burned throughout, and entirely free from lime or other impuri- 
ties. They must be laid true to the centres or lines given, and in full beds of 
mortar, with not exceeding one-fourth inch joints at the centre of the brick. The 
bed of the bricks will be on a line with the radius of the circle, and, when required 
by the engineer, a bond will be made at regular intervals connecting laterally 
the different courses or rings composing the conduit. The ordinary thickness 
of the conduit masonry will be about thirteen inches, or three breadths of brick, 
but this will be varied at the discretion of the engineer. The bricks must be 
thoroughly saturated in water just before laying, and must be pressed into the 
mortar so as to completely fill the joints. 
When stone are used they must be sound, durable, and well shaped, so that 
their beds will conform to the radius of the circle. The stone conduit will gen- 
erally be eighteen inches in thickness, but will vary from this at the discretion 
of the engineer. At least one-half of the stones as laid must extend through the 
wall; and they must be well cleaned and saturated in water just before laying, 
and laid in a full bed of mortar with not exceeding one-half inch joints. The 
outer and inner surfaces of the wall must be thoroughly pointed or covered with 
a full coat of mortar, as the engineer may direct, in order to make it impervious 
to water. 
The conduit through tunnel excavations will, when required by the engineer, 
be formed by filling up the irregularities of the lower section w;th a bed of con- 
crete or rubble masonry, as the engineer may direct; and when any portion of 
the tunnel passes through material that is not self-sustaining, and is liable to fall 
in and obstruct the passage of the water, the same will be lined throughout, 
either with a sheeting of brick or stone, as the engineer may direct, laid similar 
to the other portions of the conduit, and backed up solid against the sides and 
top of the tunnel. 
The centring for the conduit will be furnished by the contractor without extra 
charge, and will be constructed and placed as directed by the engineer. 
Specifications for cement, sand, mortar, grout, and concrete. 
Cement.-The cement used in the work must be of the best quality of hydraulic 
cement, equal in character to the Rosendale. It must be fresh, well burned and 
ground, free from foreign substances, and put up in air-tight casks. 
also be subject to such tests as the engineer may direct; and the contractor must 
keep it entirely protected from the weather until used in the work. 
Hand.-The sand used in the work must be clean and sharp, free from loam, 
dust, mica, or other impniities, which will hinder it from mixing freely with the 
cement. It must be thoroughly screened and washed when required by the 
engineer. 17 
Mortar.-All mortar used in the work will be composed of hydraulic cement 
and sand, mixed with water in such proportions as the engineer may direct, 
generally -one part of cement to two parts of sand. The materials will always 
be measured under the eye of the inspector, and whilst dry thoroughly mixed 
on a tight, wooden platform; after which a sufficient quantity of clean water will 
be applied to bring it to the proper consistency, and then it will be worked with 
hoes until all the particles have become thoroughly intermixed. The quantity 
so manufactured must not exceed the amount required for immediate use; and 
it must be applied to the work within the proper time for rendering the adhesion 
and solidification most perfect. No mortar will be used in the work which has 
been once set and worked over the second time. 
Grout.-When grout is required in the work it will be composed of the 
same kind and quality of materials, and mixed in the same proportions, as above 
specified for mortar, except that it will be manufactured in a tight box, and, by 
the addition of water, reduced to a proper consistency for running freely through 
the interstices of the masonry, or other substance to which it may be applied, 
until, when fully set, the whole mass becomes perfectly solid and impervious to 
air or water. 
Concrete.-When concrete is used in the work it will be composed generally 
of one part of cement, two of sand, and five of hard, durable rock, broken to 
pass through a two-inch ring. These proportions will be varied at the discre- 
tion of the engineer. The cement and sand will be mixed dry, and reduced to 
the proper consistency with water before the stone are added. The whole mass 
will then be thoroughly worked with hoes or shovels, and applied to the work 
immediately in layers not more than eight inches thick, each layer to be prop- 
erly confined in its place, and rammed until the mortar flushes to the surface, 
and it must become thoroughly solidified before another layer is added. 
2 W A