Consumption and waste of water in the city, as measured annually in the latter part of June of each year, from 1874 to 1894, both inclusive.

It will have been observed from the above table that the consumption and waste in the city has increased from about 27,500,000 gallons per day in 1889, the year before the 48-inch main was put in operation, to more than 49,000,000, or nearly double the former quantity.

The last census (the police census of June, 1892) of the cities of Washington and Georgetown found that the population, excluding the "county," was 228,002. Dividing this number into the number of gallons of water consumed and wasted on June 28 we find the daily rate per capita to be 215 gallons.

While this calculation is not strictly accurate, for the reason that it excludes the unknown increase of population since June, 1892, and for the further reason that while the major portion of the population of the "county" is not supplied with Potomac water a comparatively small number of persons in that section is so supplied, it is sufficiently close to show that the quantity of water wasted is greater than can be afforded before the supply from Great Falls can be increased by the raising of the height of the dam as urged elsewhere in this report.

No complaints as to the condition of the water, except in respect of its turbidity, have been made during the year.

Statements of the condition of the water in the distributing reservoir as it is supplied to the mains leading to the city after passing through the reservoir will be found in Appendix 1. A copy has been furnished monthly to the Museum of Hygiene of the Navy Department since June, 1891, at the request of the medical director in charge. A statement of the total number of days during the fiscal year 1893–294 on which the water at Great Falls, at the Dalecarlia receiving reservoir, and at the distributing reservoir was clear, slightly turbid, turbid, and very turbid will be found in the same appendix.

A table showing the pressures on the United States mains for every day in the year, as recorded on the gauges in the office of the Washington Aqueduct, will be found in Appendix 2.

MISCELLANEOUS.

In addition to the foregoing work of the last fiscal year, stated under the appropriate headings, I have to note the following:

An examination of the telephone line that connects the two reservoirs and Great Falls with this office, showing that many of the poles were decayed and in an unsafe condition, the butts of 65 poles were cut off and the poles reset and 9 new poles were planted.

The District authorities having changed the system of sewerage for the block in which the aqueduct office is situated, in order to allow the closing up of an open sewer that was a menace to the health of the vicinity, it was found necessary to lay a special sewer from the office to Rock Creek, which was done in January.

Extensive repairs were made on the aqueduct stable, on the fence at the distributing reservoir, and in this office.

Shade trees (alternate lindens and tulip trees) were planted at the distributing reservoir to replace some of those that had been planted in the previous fiscal year and had failed to live.

On May 28 I inspected the sandstone quarries at Seneca, Md., pertaining to the Washington Aqueduct.

The Secretary of War on January 9, 1894, granted to J. P. Clark a revocable license to construct a plank walk along the Conduit road from Foxhall road to Albany street.

Strong iron doors were hung at the outlet from the waste gate in the dam at wasteweir No. 3 and at the openings to the chambers in the abutments of Cabin John bridge to prevent access to these chambers of unauthorized persons.

Supt. R. C. Smead, Chief Clerk Simon Newton until January, 1894, and Pickering Dodge since that date, valve-tender and machinist Thomas Ferguson, and the other employés of the aqueduct have been faithful in the performance of their responsible duties. Thomas Sullivan, John Halloran, and Daniel Harrington, for many years watchmen gatekeepers at Great Falls and at the reservoirs, in addition to their other duties, have skillfully and energetically acted as foremen of laborers engaged on the works of repair of their respective divisions of the aqueduct.

On reference from the Chief of Engineers reports on the following bills introduced in the Fifty-third Congress, first and second sessions, have been made by me during the fiscal year:

S. 871, Fifty-third Congress, first session, "A bill to authorize the Norfolk and Western Railroad Company, of Virginia, to extend its line of road into and within the District of Columbia, and for other purposes."

H. R. 6040, Fifty-third Congress, second session, "A bill to amend an act entitled 'An act to incorporate the Washington and Great Falls Electric Railway Company.""

S. 1359, Fifty-third Congress, second session, "A bill to amend an act approved July fifteenth, eighteen hundred and eighty-two, entitled An act to increase the water supply of the city of Washington, and for other purposes.""

S. 1960, Fifty-third Congress, second session, "A bill to authorize the Great Falls Power Company to use electricity for light and power purposes in the District of Columbia."

S. 2118 (H. R. 7502), Fifty-third Congress, second session, "A bill authorizing the sale of title of United States to a tract of land in Montgomery County, Maryland, to William H. and George Bobinger."

The Secretary of War on May 14, 1894, granted permission to the Commissioners of the District of Columbia to construct under specified conditions a sewer from the Girls' Reform School across the Conduit road and the aqueduct lands to Little Falls Branch, below the dam of Dalecarlia receiving reservoir.

On the request of the District water office, permission was granted to raise the height of the water in the high-service reservoir on Road street in Georgetown 23 feet, or to the height of 220 feet above datum.

EXPLANATIONS OF ESTIMATES.

It is my duty to call especial attention to several works that are urgently needed. Most of them were mentioned in my last annual report, and in several previous reports, but have not been acted on by Congress.

Raising the height of the dam at Great Falls.-Respecting this work I quote the following from my last annual report:

During the last summer and fall the Potomac at Great Falls was at a lower stage than has ever before been known within the memory of the oldest inhabitant. On seventy-two days the gauge above the dam showed a depth of water on the dam of only about 7 inches, and on five days it showed but 6 inches. The crown of the conduit arch at Great Falls is 151 feet above datum and the crest of the dam is 148 feet above datum. The conduit was therefore (in respect of its diameter) only about three-fourths full at its head. A similar deficiency now obtains every year during the time of low water at Great Falls, and at such times, the weather being usually hot and dry and the consumption and waste in the city greatly increased, I have found ever since I laid the 48-inch main that the height of the dam is not sufficient during a considerable portion of every year to enable the conduit to deliver into the distributing reservoir as much water as is now consumed and wasted in the city, and at the same time keep up the head in the mains to 146 feet above datum, which is necessary for the supply by gravity of the high northern portions of the city and of Capitol Hill. The only remedy for this deficiency, which reduces pressures everywhere in the city and is annually increasing, except the enactment of a law requiring the use of meters by all consumers of Potomac water, is one that must be made before any further steps are taken for increasing the supply from the distributing reservoir, either by the tunnel to the new reservoir near Howard University, or by another main. It is the raising the height of the dam at Great Falls. In other words, before providing additional means of supplying to the city more water from the distributing reservoir, it will be necessary to be able to send more water from Great Falls into this reservoir.

I estimate the cost of raising the height of the dam, together with the cost of such other works as may be found necessary in connection therewith, including the cost of strengthening the conduit and including also payment for damages on account of flooding of lands and other damages, at $125,000.

As soon as an appropriation can be had for the work it is proposed to raise the height of the dam 2 feet, or to the height of 150.5 feet above datum. This would not only have the effect of filling the conduit at its intake at the lowest stages of the river, but the increase in the head of the water over the distributing reservoir would increase the velocity through the conduit, and the result would be an estimated increase in the supply to the reservoir of about 20,000,000 gallons per diem.*

I find among the interesting and instructive notes that I received from the late Gen. Meigs and have carefully filed for the information of the officers in future charge of the aqueduct, one dated March 1, 1891, of which the following is an extract:

The original design was to set the lip of the dam at the Great Falls at the height of 150 feet above tide, for which height all the profiles and wasteweirs were built. The back filling over the conduit would now allow a height of water some 2 feet higher than the dam to flow safely through the conduit, and, if needed, another foot or two and corresponding widening of the embankments would fit the aqueduct to convey, with increased height of dam lip, a very much increased flow of water to the city.

Improving the Dalecarlia receiving reservoir.-One of the most beneficial appropriations ever made for the Washington Aqueduct since its completion in 1863 was the appropriation of $60,000 made in the act of March 3, 1893, for improving the receiving reservoir by the works required for cutting off the drainage into it of polluted waters and sewage from the surrounding country, for the purchase or condemnation of the small amount of land required for the purpose, and for the excava tion necessary at the head of the reservoir, with the provisions that the whole cost of the work shall not exceed $150,000, and that the work

This is under the supposition that the appropriation hereinafter recommended will be made for removing the accumulation of deposits in the conduit.

should be done by contract or otherwise, as the Secretary of War might determine.

The object and plan of this improvement were fully described in my last annual report, and the work accomplished during the last scal year has been stated in detail in this report under the heading "The reservoirs." By means of the $60,000 appropriated for the work the main drainage tunnel under Dalecarlia hill, nearly 1,000 feet long, has been completely finished, and it has been very carefully lined with brick, exhausting the appropriation.

There remains to be done a short tunnel through the hill which lies to the east of Little Falls branch, the open channels between the three streams that empty into the reservoir, and the permanent dams across these streams. The estimate submitted is necessary for these purposes, and it is earnestly hoped that this amount will be appropriated before the close of the current session of Congress for the completion of the work.*

Storage yard. In my last annual report I stated the necessity for a yard near the aqueduct office for the storage of articles that are necessary for repairing any breaks that may occur in the 21 miles of trunk mains belonging to the United States. The storage yard on the bank of Rock Creek, in rear of and pertaining to the aqueduct office, is entirely unsuited to the purpose. It is too low, and the route from it to the level of the street being steep and tortuous, before the very heavy castings required for these repairs could be hauled out much damage and destruction of property might be done. I quote my former remarks on this subject and renew the estimate submitted:

I have provided supplies for use in case of breaks in the 48-inch and other mains, comprising sections of pipe, curves, crosses, reducers, sleeves, etc., a heavy wagon for hauling them where needed, lifting jacks, and efficient pumps; also machinery for lowering the pipes in the trenches, and the implements and material required for handling and calking.

A portion of these supplies has been placed in a yard which I have arranged on the public land at the distributing reservoir, for use in the country portions of the routes of the mains, and the remainder for use in the city portions of these routes has been placed in a portion of Twenty-seventh street, near M-street bridge, which has been loaned for the purpose by the District government until the street is wanted for improvement.

As we shall not be able, probably, to retain this place, except for a short time, a permanent yard in the city should be purchased for use as a storage yard. It should be near this office, and at or near the grade of the street, so that the heavy castings and machinery required for repairs can be quickly gotten out.

I believe that a suitable lot can be obtained by purchase, or if need be by condemnation, for $10,000, and I recommend an appropriation of this amount for the purpose.

In my last annual report and in several previous annual reports, I called attention to several other works that in my judgment were required for the improvement, the preservation and repair of the aqueduct, and submitted estimates of their cost. No appropriations having been made for these works I renew the estimates of their cost and restate explanations of their necessity:

Widening the macadam parement of the Conduit road.-The present macadam pavement of the Conduit road was only made wide enough (about 12 feet) to prevent the earth-covering of the arch of the masonry conduit under the road from being cut through by travel in spring, and at other times when the ground is softened by rain. The travel on the road in good weather, and especially on Sundays and other holidays, has increased so enormously that collisions are frequent. Wrecks of vehicles are often seen along the sides of the road on Mondays, and there is constantly danger of serious accidents by collision on the narrow pavement of this road.

The greater portion of the Conduit road is beyond the District line, but it and the

* Since this report was written the sum of $52,500 has been appropriated for continuing this work, leaving the amount yet to be appropriated $37,500.

strip of land through which it passes belong entirely to the United States. It is almost the only, if not quite the only, road out of the city that has not been spoiled for driving purposes by street railways. It is one of the most picturesque roads in the country, extending far up into Maryland amid the fine scenery along the Potomac, and it is the only route to the city that is available for a large number of the farmers of Montgomery County. Congress has refused to allow the road or any part of the strip of land referred to to be occupied for railroad purposes, and in its charter for a railway on private lands south of the Conduit road and parallel to it (that of the Washington and Great Falls Electric Railway) the marring of the beauties of the road was carefully guarded against, and the construction of more than one line of railway near the Conduit road was prohibited.

The macadam pavement should be widened to a width of 30 feet. The depth of the new portions should be 13 inches, including 8 inches of large stone, 4 inches of small broken stone, and 1 inch of binder. There should be a wide-paved gutter and a line of shade trees (preferably alternate lindens and tulip trees, on each side of the road, and the slopes of embankments should everywhere be sodded. This plan will require the widening of the roadbed at several places by adding to the width of the embankments over the culverts that pass under the aqueduct, by cutting away embankments on the upper side of the road, and by filling on its lower side.

I estimate that the cost of the work required for that part of the road that lies between the auxiliary gatehouse at the distributing reservoir and the foot of Dalecarlia hill, a distance of 13,200 feet, or about 2 miles, will be $34,500, and an estimate for it is submitted in the list of estimates. The remaining distance to Cabin John Bridge, which is the limit of the major part of the travel at present, is about 3 miles. It will probably not be necessary to extend the improvement of the road beyond this point for several years.

In addition to widening the pavement of the Conduit road as herein proposed, a width of 100 feet, or such other width as may be necessary, on each side of the road, should be purchased or condemned for the purpose of parking it, and with the additional object of controlling the land abutting on the road and excluding the liquor saloons that now exist and are increasing, and to which many of the collisions on the road are doubtless attributable.

I may remark that when the late Gen. Meigs constructed the Washington Aqueduct (it was commenced in 1853 and essentially finished in 1863) there was no road along it or in its vicinity, and the only road from Washington to Great Falls was via the Rockville road and the "River" road, which ran and now runs from Tennallytown to the Falls; but the route over the conduit being shorter and until the hills around the Falls are reached comparatively level (the road has essentially the saine grade as the conduit beneath it, viz, 9 inches to the mile, or, more accurately, 9 inches in 5,000 feet, or 0.00015), it soon attracted travel, which has been constantly increasing. Raising the masonry casings of the manholes along the line of the aqueduct.-When the water in the distributing reservoir is at its normal height of 146 feet above datum, there is a pressure of something over 4 feet of water at the crown of the conduit arch where the conduit enters the reservoir, and the water in the conduit is backed up and the crown of the arch is under pressure about as far up as Bridge No. 3, or Griffiths Park bridge, the bridge next above Cabin John bridge. I found when I uncovered the manholes along the line of the conduit for use in my inspection of its interior from Great Falls to the distributing reservoir in September, 1891, that the tops of several of the casings of the manholes below this point are below the gradient or slope of the water, so that when the manholes are uncovered it is found above the manhole covers, and in some instances more than a foot in depth above them. No harm has thus far resulted from this state of affairs, but the casings of the manholes wherever necessary (I have a record of them) should be raised above the gradient, so as to prevent the soakage of the ground around the manholes. An estimate of $600 for this work is submitted.*

Lowering the height of the cross dam in the distributing reservoir.-The lower reservoir (the distributing reservoir) is divided about halfway between the influent and effluent gatehouses by a cross dam, in the middle of the length of which is a narrow cut lined with masonry, through which all the water on its way to the effluent gatehouse, where it enters the mains, must pass.

The draft through this cut is so strong that the major part of the water is drawn straight from the influent gatehouse, which is in an angle of the upper division (the settling division), to the cut, so that when the water is turbid it does not diffuse itself through the whole body of water in this division (110,000,000 gallons) as it should, in order that the greatest amount of settling be done.

Neither is the water after it passes through the cut properly distributed through the lower division, which contains about 60,000,000 gallons, for the reason that the draft from the cut to the head of the mains leading to the city from the lower end *This work must be done before the height of the dam at Great Falls is raised.