In the beginning of the motion, the column of water adhering to the rope, is always less than when it has been worked for some time, and continues to increase till the surrounding air partakes of its motion. By the utmost efforts of a man, nine gallons of water were raised by one of these machines from a well, ninety-five feet deep, in one minute. (_Adam’s Philos._)
_The hydraulic belt_ is a similar contrivance. It is an endless double band of woolen cloth, passing over two rollers, not here shown. It is driven with a velocity of not less than a thousand feet per minute; when the water contained between the two surfaces is carried up and discharged as it passes over the upper roller, by the pressure of the band. Some machines of this kind are stated to have produced an effect equal to seventy-five per cent. of the power expended, while that of ordinary pumps seldom exceeds sixty per cent. (_Lon. Mechan. Mag._)
_Spray Pump._ Fig. 173 exhibits a carefully designed pump made to spray trees, plants, etc. All the working parts are of brass, the valves are metal; the air chamber is made of galvanized iron or copper and has large capacity. It will hold sufficient compressed air to keep the spray going from six to ten minutes after the pumping stops. The “agitators” are placed so that they keep the liquid thoroughly stirred. The plungers can be easily removed and packed without the necessity of taking the pump to a shop.
The pump is fastened to the bottom of the barrel by a bolt passing through the barrel and secured by a nut underneath, with packing to prevent leakage, and by an iron plate at the top covering the opening through which the pump is placed in the barrel. This pump is arranged with one, or two levers, and for one or two lines of discharge hose. The cylinders are 2-1/2 inches diameter with stroke 3 inches; its capacity per stroke is 0·13 gal.
_Combined Pump and Horse Power._ The “horse power” (apparatus) with its “pole” for one horse and two poles for two horses and its wrought iron “tumbling shaft” has been so modified that a horse operates the pump, by means of a “sweep,” direct connected to the pump crank shaft.
The animal will make three to four circuits per minute, giving the pump crank shaft a speed of 40 to 50 revolutions per minute. The capacity of a 4 in. plunger and 8 in. stroke is given as 3·120 gallons per hour; the suction pipe is given as 3-1/2 in. diam. and the discharge as 3 in. pipe.