In June, 1889, a test of this engine was made by Prof. James E. Denton, who says con cerning it : The boiler evaporates 8.88 lbs. of water from 104° F. into steam of 127 lbs. pressure with anthracite coal yielding 14 per cent. of ashes at 5 lbs. rate of combustion, and lbs. of water from 104° F. with Georges Creek bituminous coal yielding 10 per cent. of ashes at 5 lbs. rate of combustion. The en gine performs it horse-power of work in its steam-cylinders with a consumption of lbs. of steam per hour. Taking into account the percentage of ashes, the performance of the boiler is practically the maximum econ omy to be expected or gotten from boilers, while the steam consumption of the engine is also unexcelled, as even the most approved marine engines of the triple-expansion type, using steam at 150 lbs. pressure. have yet to produce it 'coon] of steam consumption lower than 15 lbs. of steam per hour per horse-power. The combined efficiency of the boilers and en gines give a horse-power in the steam-cylinders with lbs. of anthracite coal consumed per hour, and 1.4S lbs. bituminous coal consumed per hour. Out of a horse-power produced in the steam-cylinders, 95 per cent. is available to force water, only about 5 per cent. being re quired to overcome the friction of the mechanism and operate the air-pump. In this respect also the engine is an extraordi nary piece of apparatus. It re sults from all of the foregoing that the duty per 100 lbs. of coal was for anthracite coal, 121, 750,000 ft. lbs., and the duty per 100 lbs. of coal was for bituminous coal, 127,350,000ft. lbs. These figures are for the actual evaporation of the boilers as given above, This engine made an average duty record for the entire year 1858 of 124,512.184 ft. lbs. per 100 lbs. of coal used.
Allis'.. Compound VerHcal P umping -engin es. —Figs. 4 and 5 illustrate a pumping engine constructed by E. P. Allis & Co., of Milwaukee, for the city of Milwaukee. The low-pressure cylinder is placed on the top of the wrought-iron framework, and directly central over the high-pressure cylinder, which is on a level with the engine-room floor, the pistons of the two cylinders being connected by two piston-rods. The rod for operating the bucket and plunger pump is fastened to the high-pressure piston and extends through a stuffing-box in the bottom head to the bucket and plunger pump placed in the pump pit. By this means all the steam-cylinders arc coupled solidly to the pump plunger. Both steam-cylinders are steam-jacketed and furnished with a device for regulating the point of cut-off and speed of the engine. The following are the principal items of interest from a test trial : Duration of trial, 48 hours : steam pressure in engine room, lbs.; vacuum by gauge, in.; water-pressure gauge, lbs.; total head, including suction lift, lbs ; revolutions of engine per minute. ; piston speed per minute, ft.; coal consumed, 32,395 lbs.; duty in foot pounds per 100 lbs. of coal consumed, 104.820,431. The test was made under
the ordinary every-day conditions, and the actual weight of coal consumed was charged up without deductions of any kind. This engine raised 12,000,000 gallons 150 ft. high in 24 hours.
Reynolds' Screw Plimping-engine.—One of the most novel forms of pumping-engine that have been built in recent years is that shown in Fig. 6, designed by Mr. Edwin Reynolds, superintendent of the E. P. Allis Co., for flushing the sewer tunnels of the city of Milwaukee. The pump is a form of propeller-wheel, with screw-shaped blades. This is mounted in a cast-iron circular housing or casing set in the brick walls of the tunnel. The wheel is keyed to the crank shaft of the Reynolds vertical compound condensing engine. Bearings for supporting the outer end of the shaft are formed in the wheel casing. In tests of the engine the duty was computed from the quantity of water discharged through the tunnel, and the total amount of coal fired to the furnaces, without deductions or allowances of any kind. The quantity of water discharged was determined by injecting bright carmine color ing matter into the center of the water current in the tunnel and noting the time elapsing before the coloring appeared at the discharge outlet, 2,534 ft. distant. These tests were repeated to establish a fair average of the quantity of water discharged per revolution of the engine when running at 52 revolutions per minute. The results of the official trial were as follows ; Date of trial, December 1st and 2d, 1888. Duration of trial, 24 hours: average steam pressure by gauge, 102 lbs.; average vacuum by gauge, 26 in.; average revolutions per minute, 51.845 ; cubic feet of water raised 3.049 ft. per revolution, ; loss of action in wheel, due to head and friction, 13.28 per cent.; efficiency of wheel. 87-56 per cent.: total coal fired to furnace, 14,750 lbs.; total water fed to boilers, 109,890 lbs.; temperature of feed water, 120•G2° F.; water evaporated per lb. coal, 7.45 lbs.; duty, water raised per 100 lbs. coal used, 75,944,424 ft. lbs.; duty, water raised per 1,000 lbs. steam used, 101, 936i,504 ft. lbs.
Geared .31ine Pump.—Fig. 7 shows type of pimping-engine built by E. P. Allis & Co.. and used for pumping out mines. The top of the bob" is shown projecting through the floor ; this is made to fit any location or conditions. The rods connecting the "bob " with the pumps and crank are made any size or length. depending on the depth of the shaft and its distance from the engine ; these rods are supported by trucks and rollers or carrier arms as desired. The common design of single-acting Cornish pumps is usually adopted for this service. The pumps are driven by a Reynolds Corliss engine, by means of a shrouded step tooth pinion and gear of such proportions that the engine will run at a fair rate of speed while the pump plungers move at a slow speed when running at rated capacity.