History of the Water Supply of the World / arranged in a comprehensive form from eminent authorities, containing a description of the various methods of water supply, pollution and purification of waters, and sanitary effects, with analyses of potable waters, also geology and water strata of Hamilton county, Ohio, statistics of the Ohio river, proposed water supply of Cincinnati.

SUMMARY OF FLOW OF RAIN-FALL IN CU. FT. PER MINUTE PER SQUARE MILE.—(From Fanning.)

AQUEDUCTS.

The plan, as adopted by Mr. Hawskley at Liverpool, and Mr. Bateman at Glasgow, of subterranean pipes, is now universally followed by engineers. And there is no longer any excuse for incurring the outlay which must attend the erection of monumental structures, such as were necessary in the times of the ancient Romans.

The engineer of Marseilles Conduit adopted the “Pont du Gard” plan for conducting the waters of the Durance, in preference to iron pipes, and constructed the splendid folly, “as Humber terms it,” of the aqueduct “Roquefavour.” The dimensions are:

The cost was $750,000, while inverted syphon pipes could have been laid for one-third of this sum.

The aqueduct for Glasgow is thirteen miles in tunnels, 3¾ miles of iron-piping across valleys, and nine miles of opening cutting and bridges. There are eighty distinct tunnels, and twenty-five important iron and masonry aqueducts. On the line is the Drymen bridge on masonry piers, eighteen feet apart, with two pipes surrounded by wood lagging, a forty-eight-inch syphon at Aberfoyle Road, and a lofty bridge at Ballewan, seventy feet in height.

The Aberdeen water-works has a thirty-six-inch syphon, 1,200 feet in length, across Cullen Burn, supported by granite piers.

The Croton aqueduct is a masonry channel lined with brick. The bottom is an inverted arch with cord 6.75 feet, and versed sine 0.75 feet; side walls are 4 feet high, and battered so that at the top they are 7′ 4″ apart, and surmounted with a semi-circular arch. The interior is 8.64 feet high, and area 53.34 square feet.

The grade is 0.021 feet per 100 feet, total length 38 miles. It crosses the Manhattan Valley 2 miles in extent, with two 36-inch, one 48, and one 60-inch cast-iron pipes, and over the Harlem River by granite bridge, known as High bridge, 100 feet above high water, composed of seven 50-feet and eight 80-feet spans. The conduit over the bridge consists of two 36-inch cast-iron pipes, and a wrought pipe 7 feet 6½ inches in diameter, resting upon saddles, supported by cast-iron standards placed 12 feet apart between the 36-inch pipes.

The aqueduct over Cabin John Creek, of Washington, D. C., water supply, consists of a single arch of masonry 220 feet span, is the largest masonry arch in the world. The rise is 57 feet 7 inches, thickness of crown 4 feet 2 inches, and at spring 6 feet 2 inches. Water is conveyed in an iron pipe 9 feet in diameter, built in solid masonry.

The bridge over Georgetown Creek, on line of Washington Conduit, is 200 feet span with two cords of iron pipe 4 feet in diameter, 1½ inches thickness, used as water conductors. The pipes were first lined with staves of resinous pine 3 inches thick to prevent freezing, but have been taken out. No allowance is made for expansion or contraction. A similar plan is in use at Philadelphia, over the valley of Wissahikon, consisting of two 20 inch cast-iron flange pipes serving as top members of a series of inverted bow-string trusses. There are four spans, each 169 feet 9 inches. Center span 100 feet above ordinary level of the water.

The Boston aqueduct crosses the Charles River by syphon pipes—two, 30 inches, and the other 36 inches in diameter. Starting from a pipe chamber on the western side of the valley, the pipe descends 52.11 feet below the level of conduit, and rests on a masonry bridge of three arches.

One of the syphons for supplying Madrid, Spain, crosses a valley 4,560 feet in length, consisting of four lines of cast-iron pipes three feet in diameter.

Dublin is supplied through 30,336 yards of 33-inch and 8,272 yards of two lines of 27-inch cast-iron pipes—20,000 yards laid through private property. The average fall is 20 feet per mile. There are three relief-tanks on line of 33-inch pipe. The capacity of this pipe was calculated at sixteen millions per day, while the actual delivery exceeded twenty millions.

Toronto is supplied by a 4-foot wooden pipe, 7,000 feet in length, under pressure.

Manchester, N. H., has a wooden penstock, six feet in diameter, 600 feet in length, that conveys supply to water wheels, under a head of twelve feet at entrance and thirty-eight feet at outlet.

The new conduit for water supply of Baltimore is a continuous tunnel, seven miles long, running from the dam to the receiving reservoir—“Lake Montebello.” In its construction no open cuts were made; all work being done by drifting. Its depth below the surface of ground varies from 65 to 360 feet. The internal diameter is 12 feet; the fall is one foot per mile; capacity 170 millions daily. Fifteen shafts were sunk during the constructive work. Two miles of the tunnel were through material that required to be arched with brick; the remaining distance was through very hard rock that did not require arching. The cost of this structure was about two millions of dollars.

Chicago has two tunnels under Lake Michigan, parallel with each other, 46 feet apart, extending to a crib, located in the lake, two miles from the shore. The first one was started, in 1864, under adverse criticism, and successfully completed in 1867. The cost, with the crib, was $457,800. It is five feet horizontal diameter, and 5′ 2″ vertical diameter, and made of brick. The second one was built in 1872-’74; is five feet in diameter, lined with brick. It extends from the North Side Works, a further distance of 20,000 feet, under the city and Chicago River to West Side Works. The cost of this tunnel, under the river, was $414,000, and under the city $543,000. The nature of the excavation was generally through stiff blue clay with occasionally pockets of quicksand.

The Sudbury conduit, of Boston Water-Works, is sixteen miles long, with a grade of 1.056 feet per mile. The top is a semicircle of nine feet diameter, and the bottom is an arc of 13.22 feet radius, struck from a center 5.53 feet above the crown of the arch. The sectional area is 56.75 square feet. The foundation is of concrete; the side walls and spandrel backing of rubble stone masonry; the lining of brick, four inches thick, and the arch of brick, twelve inches thick. The Charles River is crossed by a granite bridge, 475 feet long and 75 feet high, with two segmental and five semicircle arches.

On the line of the Vanne conduit there is an aqueduct made entirely of “beton,” which spans the valleys and quicksands in the great forest of Fontainebleau, between La Vanne River and Paris.

CONDUIT DATA.—(From Fanning.)

DAMS.

The disastrous failures of earth dams has excited suspicion as to the stability of such structures; but when we consider the immensity of the dams in India, our concern should be only for the care and attention given to their construction. There the material used is well puddled; then a drove of cattle is turned loose on the fill, to stamp the earth thoroughly. This method is repeated in layers until the required height is reached. Often the Sepoys do the stamping.

The Veranun reservoir dam is twelve miles in length; and the amount of earth, of which it is composed, will encircle the globe with a belt six feet in thickness.

There is a dam on the island of Ceylon made of huge stone blocks strongly cemented together and covered over with turf, making a solid barrier of fifteen miles in length, one hundred feet wide at the base, sloping at top to forty feet, and extending across the lower end of a spacious valley.

DIMENSIONS OR RESERVOIR DAMS.—(From C. H. Beloe.)

One of the recent dams of the Croton supply, made of concrete, is thirty-one feet at the base, eight and one-half feet at top, six hundred and seventy feet long, and seventy-eight feet high. The main embankment, which forms Lough Vartry of the Dublin Water-Works, is sixty-six feet high at its deepest part, and the greatest depth of water, sixty feet. It is 1,640 feet long on the top, and twenty-eight feet wide, which forms a public road. The base, at the deepest part, is 380 feet wide; the inner slope being 3 to 1, and the outer slope 2½ to 1, and the total quantity of earthwork in it is 320,000 cubic yards. The puddle wall in the embankment is six feet wide at the top (one foot below the top bank), and eighteen feet wide at the level of the old river bed. It was carried, for its entire length, down into solid rock.

The dam of Bradlee basin, Boston, is 2,000 feet in length, twenty feet wide on top, one hundred and fifty feet at the base, and greatest height thirty-five feet. In the center of the bank is a puddle wall ten feet thick at the base, and four feet at the top, founded on the rock. The earth embankment was laid in layers, well watered and rolled.

COMPARISON OF LARGE GRAVITATION WORKS.

The dam for diverting the waters of Gunpowder Falls, for supply of Baltimore, is built of rubble and white marble upon solid rock. Thickness at base is sixty-two feet; depth of foundation below original surface is thirteen feet; width of the overflow is three hundred feet. The wings extend into the hill on each side two hundred and fifty-six feet. The height from the extreme foundation to the overflow is twenty-nine feet. The filling of the clay and earth on the inside is forty-five feet at the base.

Liverpool, Eng., designs constructing a masonry dam, at the source of the new supply in Wales, eighty-four feet in height.

PUMPING SYSTEM.

The divisions of power are:

And the methods of supply by:

The value of a pumping system recommends itself on the point of economy in construction, for the outlay is in proportion to the existing necessities, which can be increased as the demands require. The original water consumers are not, therefore, taxed so heavily for future exigencies of gravity works. This idea can be better illustrated by the comparative cost of construction and maintenance of gravitation and pumping works:

The reservoir system is the most preferable of the three methods, when natural elevation can be secured, for the pumping service is distinct from the distribution; and, where reservoirs of large capacities are obtainable, a closer margin for reserve pumping power can be adopted, besides a storage reservoir provides for contingencies that may arise, and allow cessation of pumping during the turbidity of water source, caused by sudden freshets.

The stand-pipe is adopted where the elevated grounds are not sufficient for reservoir purposes, to give a desirable water pressure; or where reservoirs may not be desired, but to secure the head and provide for a constant and reliable action of the pump that is not obtained by a direct system.

The direct system, commonly called the Holly Plan, does away with reservoir and stand pipe, and delivers the water directly into the mains under a pressure usually fifty pounds per square inch for domestic use, which is increased to one hundred pounds when fires occur. In the Holly Plan, a reserve power is used for fire purposes, besides mechanical device for regulating and controlling the variable pressure.

In either the stand pipe or direct system, a reserve power should be provided equal to the largest daily consumption.

From a compilation of general information concerning water-works of the United States and Canada, published by the Holly Manufacturing Company in 1878, we arrange the following:

Of the above number of pumping works—

The expense of pumping water by steam and water-powers, also the practical yearly duties of various pumping engines, are given in the tables on pages 61 and 64, compiled from annual reports for 1880:

PRACTICAL DUTIES (WITHOUT DEDUCTIONS) OF PUMPING ENGINES (YEARLY AVERAGE).

(From Annual Reports of 1880.)

Remarks.—