The term, duty of a pumping engine, is a conventional one, used by engineers to measure the relative merits of performance, or effective work, expressed by the ratio of product in foot pounds of the weight water into the height it is lifted, to one hundred pounds of the coal consumed to lift the water. The following tables of expert trials are taken from “Manual for Engineers and Steam Users,” by John W. Hill, M. E. (1878), with a few additions:

PERFORMANCE OF PUMPING ENGINES.

PERFORMANCE OF PUMPING ENGINES.

(A. S. C. E. is the American Society of Civil Engineers.)

COST OF PUMPING ONE MILLION GALLONS OF WATER,

(From Annual Reports, 1880.)

STAND PIPE.

New York has a stand-pipe, for high service use, 170 feet high.

Cleveland has a stand-pipe 148 feet high, 36 inches in diameter.

The stand-pipe at Louisville is 48 inches in diameter, 132 feet high, made of ¼ to ½-inch wrought-iron plates, the whole incased in wood.

The Mt. Auburn High Service at Cincinnati is supplied by two wrought-iron tanks (which answer the same purpose of stand pipes), each 60 feet in diameter and 38 feet high, and made of wrought-iron sheets 50″ by 140″, ¼″ to 7-16″ in thickness. The water surface is 483 feet above low water. The cost of each tank was $15,000.

The water-tower at Toledo consists of a wrought-iron stand pipe, around which is built a masonry structure of solid stonework 36 feet square, commencing 16 feet below the natural surface, with a vertical thickness, under base of stand-pipe, of 7 feet; thence, with octagonal opening around the pipe, to a point near 3 feet above the surface of the ground, at which point its inner diameter is 16 feet, and outer dimensions 30 feet square. From this point, to a further height of four feet, the wall is composed of ashlar-face and brick backing; thence to a point 70 feet above the foundation of solid brick-work with octagon interior and exterior squares, the corners terminating in buttress walls; the top to be octagonal battering to an external diameter at the top of 14 feet. The total height is 224 feet, and the cost about $25,000.

A steel plate stand-pipe designed by J. D. Cook, civil engineer for Springfield, Ohio, is in course of erection by the Stacey Manufacturing Company of Cincinnati, which will be 112 feet high, 30 feet in diameter, thickness of lower ring being 25-32″, and upper ring 3-16″. The estimated cost is $35,000.

The stand-pipe of Southwark and Vauxhall Water-Works, London, is 178 feet high, made of three columns of cast-iron pipe, the center one extending 50 feet higher than the other columns. The side pipes are 30 inch, and center 48 inch in diameter. The Grand Junction works, London, has a similar structure of two columns 153 feet high, incased in a brick structure.

The stand-pipe of East London Co. is 240 feet high and 3 feet in diameter.

HUSBAND’S PATENT BALANCE VALVE.

This patent is designed to supersede the costly stand-pipe. Fixed vertically, as near to the engine as practicable, is a strong casting provided with two short-flanged branches, the lower one being connected with the discharge outlet from the pumps, and the upper one with the delivery main. Between these branches a gun-metal valve of the double-seat description is placed, and is connected to an additional water-tight hat working on the top of the valve-seating. The seating is firmly held down by bolts passing through it and fastened to the casing. A ram lined with gun-metal, and of the same diameter as the upper valve, is secured water-tight into it by a colter, and works vertically up and down, passing through a stuffing-box packed with cup leather, bolted to the upper portion of the casing. The head of the ram works in a cross-guide lashed with gun-metal, and supported by four strong vertical pillars. The ram is loaded with weights nearly equal to the minimum load of the engine; the lowest weight is provided with lugs working loosely over the vertical pillars, which are provided with adjusting nuts and leather washers, for the purpose of preventing the valve from falling heavily and injuring its seating. The action of the apparatus is as follows: The water, on entering the casing from the pumps, acts upon the under side of the upper valve. The area of the valve is the same as that of the ram, which, being loaded somewhat under the working load of the engine, is immediately lifted, raising the valve with it, and thus giving the water free access to the delivery main.

In the event of the main being fractured at any point beyond the valve, the pressure within the main is suddenly reduced on account of the great escape of water, and is, consequently, unable to support the loaded valve, which immediately closes; thus the working load of the engine is retained, and the possibility of accident by racing prevented.

FUEL EXPENSE FOR PUMPING COMPARED ON DUTY BASES.—(Fanning.)

DIMENSIONS AND COST OF CONSTRUCTING PUMPING ENGINES.