4,594; urinals, 321; sinks, 9,190; engines, 42; hydrants, 5,024; fountains, 70; total number of spigots, 29,959. In this number leaks were discovered as follows: closets, 255; baths, 19; basins, 14; sinks, 90; hydrants, 37; number of spigots, 140; total number of leaks, 395.

CENSUS OF HOUSES IN THE DISTRICT.

In my last annual report I embraced a complete census of the houses of the cities of Washington and Georgetown, as follows:

This year the census of houses was not taken, but adding the number of houses erected during the past year will give an absolutely correct census of houses in the District. A fact worthy of mention at this point is that in most of the old dwellings owners have been compelled to introduce water, or allow their property to remain idle. This is the universal admission of those who own houses of any pretension, and proves that tenants are not willing to forego the water-privilege, even at the expense of paying additional rent.

WATER-METERS.

The subject of meters for the supply of large cities is still attracting the careful consideration of the water-authorities and civil engineers in all countries. In Liverpool, England, where each house is supplied with water through cisterns, as is shown by a recent report of the "borough and water engineer," after a series of experiments to prevent the waste of water, the authorities finally decided upon what is known as the intermittent supply; in other words, during certain hours of the night the supply was drawn off from all the mains, thus leaving the inhabitants only such water as they may have stored in their cisterns during the day. This effected a considerable saving, but the system was so objectionable to the water-takers that, in order to prevent the willful waste and still have a constant supply, an automatic contrivance known as the waste-water meter was adopted. This instrument, which is attached to the main, records the time and rate of flow through it, after the manner in which an indicator-diagram records space and pressure. It registers not only the change of velocity induced by the closing of any stopcock during the night, but the time at which the men began and ceased to work.

The city is divided into 120 waste-water districts, the largest of which contains 4,271 inhabitants, the average being 2,557. The meter is fixed in a central position, and the ordinary intermittent supply of waste having been ascertained, the district is placed under constant service through the meter for from twenty-four to forty-eight hours. The num ber of residents or takers is then ascertained and stop-cocks attached to the service-pipes of all premises.

The diagrams, both for constant and intermittent service, are worked out and entered upon a suitable book. A corps of night-inspectors are

furnished with copies of said diagrams, and, commencing at 11 p. m., begin their inspection.

They subject each stop-cock on the side walk to a test, to ascertain if water is passing into the premises. If on applying the key to the stopcock plug and the ear to the key no sound is heard, the cock is turned until nearly closed, and if water is passing, will then, by reason of its increased velocity, be readily heard.

In this manner, it is claimed, the flow due to a quick dropping can be easily heard, and this is considered evidence of waste on the inner side of the stop-cock. These cases are all minutely reported, and in the morning the reports are turned over to the day-inspectors, who make a most thorough examination of the premises reported for leaks, &c., and, as a rule, it is found that the pipes or fittings are defective and leaky. This system, it is claimed, has been the most successful yet attempted for the prevention of waste in the city of Liverpool, but at a recent meeting of the institution of civil engineers of England the representatives from London, Manchester, Dover, Norwich, Glasgow, and other cities, after a full discussion, failed to unite in agreeing to the system as a proper or safe one. Its annual cost thus far has been about $150,000, which immense sum the people of a city of 600,000 inhabitants pay to prevent the improper use of water, and then receive only an average of 16.47 gallons per head per day. Of course it would be impossible to adopt such an expensive and complex system in this city; besides, in my judgment, the better method of discovering leaks and waste in private houses is by house to house inspection; and to prevent the waste in business and manufacturing places, hotels, &c., I renew my recommendation of last year, that meters be placed on all premises other than private residences, and that a moderate rental per gallon be charged for the water used.

RECOMMENDATIONS TO PREVENT WASTE.

As a further precaution to prevent waste in private residences, I recommend that more stringent rules than have yet been adopted in regard to the class of fixtures to be used and the persons to whom they are intrusted should be adopted. To secure this end I suggest the following as alike just to the water department, the plumbers, and consumers: 1st. Before any plumber shall perform any service in a building where Potomac water is used, he shall be duly licensed, shall be a citizen of the United States, twenty-one years of age, shall have a permanent place of business in the District of Columbia, shall furnish satisfactory certificates from two licensed plumbers of his practical instruction in the business, shall give a bond for faithful work, shall make no alterations or additions to the fixtures of any premises without notice to or consent of the water department, shall make monthly returns of work done by him calculated to increase or decrease the water rate of premises and of all work put into newly-erected premises, and the water shall not be turned on until all the fixtures, pipes, &c., have been examined and tested to the satisfaction of the water department.

2d. No class of fixtures shall be in use, or no material or work furnished, except such as is approved by the water department.

3d. Running closets and urinals will not be hereafter introduced, and those already in must be substituted by self-closing fixtures.

4th. Potomac water used in hotels, restaurants, dye-houses, breweries, livery-stables, &c., shall be charged by meter measurement.

GEORGETOWN.

The system of water-supply in Georgetown differs from that of Washington so far as relates to distribution and arrangement. All that part of the city below the level of 100 feet is supplied direct from the 12 and 30 inch mains in Bridge street, and all that portion of the city 100 feet above tide is supplied from the high-service reservoir, corner of High and Road streets, the same being fed from a 10-inch main from the steam force-pump located on Fourth, near High street. This pump is supplied by a 12-inch main connected with the large main in Bridge street. In January last the old pump becoming useless by constant wear, a new one of greater power and capacity was substituted. The new pump is one of Knowles's patent, with the latest improvements attached. It has so far given general satisfaction, both as to capacity, power, and durability. In December a break was found in the highservice reservoir, caused by a leak from an old stop-cock that was attached to the main pipe, and which was carelessly allowed to remain and covered over by the workmen when the reservoir was built, and also a leak from the forcing-main, which, to some extent, undermined the bottom of the reservoir. The water was shut off by order of the engineer in charge of the Washington Aqueduct, and remained off for a period of nine months, during which time we were obliged to pump the water direct into the iron mains, and, to avoid inconvenience to citizens as well as to afford protection to property against fire, the pump was worked continuously, except when it became necessary to clean the boilers and renew fire-brick; but during this period at no time was it necessary to make any repairs to the pump or machinery attached thereto, as it run smoothly from the first and to the entire satisfaction of the department as well as to the engineer in charge.

During the period above referred to the pump run 274 days, 6,578 hours, 394,560 minutes, averaging 34 strokes per minute, at 32 gallons to the stroke, thus lifting 429,281,280 gallons of water.

We now pump daily (12 hours) 875,520 gallons, and run at an average of 38 strokes per minute, lifting 32 gallons each stroke, and, as a matter of record and information, I give a correct description of the pump, as follows:

The dimensions of the engine are: diameter steam-cylinder, 24 inches; diameter of plungers, 18 inches; length of working stroke, 253 inches; which gives a plunger displacement of 6,425.11 cubic inches, or 27.81 gallons. The style of the pump is direct-acting, the steampiston and the water-plungers being rigidly connected in a straight line, so that the movement of one part produces a corresponding motion of the other. The pump is in every particular self contained. The waterend and steam-cylinder, to which all movable parts are attached, are mounted on a heavy cast-iron frame or box-bed, and are securely held in position by large steel bolts. The plungers are connected with heavy wrought-iron guide-rods, running from end to end, and which are secured to cast-iron yokes, forming a part of the plunger-heads. The forward yoke, directly opposite the steam-cylinder, is also connected with the steam-piston rod, and, on motion being given to this part, it is communicated to the plungers, and in the same straight line. The water valves are of rubber, and 84 in number. They are 3 inches in diameter by inch thick. The area of opening through each valve-seat for the passage of water is 5.4 inches. The valves are contained in heavy plates. The pump has a 12-inch suction and 10 inch delivery-opening on each side of chest, both of which can be connected up if required. The

plunger on auxiliary valve moves in patent gun-metal casing, being made in two parts, and one end of each part being flanged. They are made to slide easily into the chest, and are held in position by the steamchest bonnets, which bolt up against their respective flanges. The object of this casing is to do away with every possibility of the sticking of the auxiliary valve, and which is accomplished by the varying expansion of the two metals, viz, the valve, which is of iron, and the valve casing, made of composition. The weight of the pump is 25,000 pounds.

The pump was tested July 27, 1876, on a run of twenty-four hours, and under the following conditions and results: A log was kept by the engineers in charge, noting the pressure in delivery-main every halfhour, and the remaining position of the log being noted once or at the expiration of the hour. Indicator-cards were taken each hour from both ends of the cylinder, and the average horse-power figured therefrom; the steam-valves were properly set, and the steam-piston found to be perfectly tight; the exhaust was free, that line coming very near to atmospheric line, and the compression or cushion brought up to nearly eight pounds at the completion of the stroke. This served to bring the piston to an easy state of rest, and as it was as easily started in the opposite direction, the pump ran smoothly and without any perceptible jar on the delivery-pipes. The steam-pipe leading to steamcylinder was not covered, and from which there was a slight loss from radiation. The conditions as averaged from the log are as follows: Average steam-pressure in boiler by gauge for the twenty-four hours, 40 pounds; average initial pressure in steam-cylinder by indicator, 35 pounds; average water-pressure on delivery-main, 52.5 pounds; total number of strokes taken by counter, 39,806; consumption of coal in pounds, 4,148.5; temperature of feed-water, 750; amount delivered by pump in United States gallons, 1,107,004.86; velocity of water through delivery-pipe, 187.9 feet per minute; the average indicated horse-power is 24.72 for the twenty-four hours' running. The theoretical or horse power utilized in delivering this quantity of water against a pressure of 52.5 pounds, through the 10-inch main, is 23.25, which shows the engine to have been in perfect condition, and the friction of the moving parts to have been reduced to a minimum. Taking the above data, the duty will read as follows: 26,880,820 pounds raised one foot high with 100 pounds coal, or 30,015,253 pounds raised one foot high with 112 pounds coal.

The last session of Congress passed the following law in reference to the collections of water-rents in Georgetown:

Extract from a bill for the support of the government of the District of Columbia for the fiscal year ending June 30, 1877, and for other purposes.]

SEC. 18. That all laws and ordinances now in force in the city of Washington relating to the payment and collections of water-taxes and taxation for water-mains be, and they are hereby, extended to and made operative over all parts of the District of Columbia where water, taken from the United States aqueduct, is used, and said taxes and rents shall be payable and collectible therein in the same manner and at the same rate as in the city of Washington for the year beginning January 1, 1876, and for each subsequent year.

Pursuant to the above, this department assessed six hundred and fifty-four houses for water-rent, amounting to $5,608.12, of which $4,903.67 has been collected, leaving a balance of $704.45 due on the vacant and cut-off houses. The whole number of water-takers in Georgetown are six hundred and sixty-five, classified as follows:

The water-mains in this city were originally laid under an ordinance of the late corporation, approved May 9, 1859, providing for a water-tax. This ordinance was in conformity with the act of Congress, March 3, 1859, both of which are here given:

AN ACT to authorize the corporation of Georgetown, in the District of Columbia, to lay and collect a water-tax, and for other purposes.

Be it enacted by the Senate and House of Representatives of the United States of America in Congress assembled, That the mayor, recorder, aldermen, and common council of Georgetown, in the District of Columbia, shall have full power and authority to levy and collect a tax not exceeding sixty cents per front foot on all lots and part of lots within said corporate limits, in front or parallel to which water-mains have been or may hereafter be laid; or, in their discretion, to appropriate from the corporate funds generally so much money as may be necessary to supply the inhabitants of said town with Potomac water from the aqueduct, mains, or pipes now laid, or to be laid, in the streets of said town by the United States; and to make all laws and regulations for the proper distribution of the same, subject to the restrictions prescribed by this act and the act approved March 3, 1859, entitled "An act to provide for the care and preservation of the works constructed by the United States for bringing the Potomac water into the cities of Washington and Georgetown for the supply of said water for all Government purposes and for the uses and benefit of the inhabitants of said cities.

And the corporation of Georgetown passed the following ordinance, based on the above act:

SEC. 2. And be it further ordained, That the mayor be, and is hereby, authorized, whenever and as the same may be needed in the prosecution of the work, to issue the stock of this corporation, bearing interest at the rate of six per cent. per annum, and redeemable, at the pleasure of this corporation, within ten years, in such sums as may be required, provided the whole amount shall not exceed fifty thousand dollars, for the purpose of introducing water throughout the city.

SEC. 3. And be it further ordained, That, to enable this corporation to redeem said stock and pay the interest thereon, and pay other expenses attending the introduction and maintenance of the water establishment, there be, and is hereby, levied a watertax of sixty cents per foot on every front foot, on each side of every street, lane, or alley through which the water-mains have been or may be laid hereafter; and that said tax shall be collected by the collector of this corporation, under the laws already passed for the collection of the general tax of this town, as follows: One-fourth annually, commencing the first day of July, 1859, viz: He shall collect fifteen cents of the above tax in that year, fifteen cents in the year 1860, fifteen cents in the year 1861, and fifteen cents in the year 1862; and he shall pay over to the clerk of this corporation such sums as he collects, retaining three per cent. as his compensation for collecting the same; and the clerk shall place said funds, as he receives them, to the credit of the water-fund, and the same are hereby pledged for the payment of the interest and the redemption of the principal of all the stock that shall or may be issued under authority of this ordinance.

In addition to the foregoing, special appropriations were made by the corporation from time to time out of the general fund for the repairs of