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Globe, Volume XX, Issue 1513, 21 December 1878, Page 3

non-condensing engine with, capacity of 2,000,000 gallons of water per 24 hours to the same altitude. Steam cylinders of compound cm ine are—high pressure 25in., and low pressure 43 8-10 in. diameter, and 3Fin. pißton Btroke ; diamoter of double acting plunger, 17|in. In the high pressure engine the steam cylinders are 24in. diameter, and 26in. piston stroke; plunger, 16in, diameter. Both engines being direct acting, the plungers and pistons being attached to the same rods respectively, the plunger and piston strokes are of course identical in length and velocity, and the theoretical displacement of water at each stroke in equal to tho area of plunger, multiplied by tho length of stroke less onehalf the solidity or volume of piston rod in water cylinder. The area of plunger in compound engine being 240| squnre inches, with stroko 36in., and one-half the volume of piston rod boing 127 cubic inches, we have a displacement for eacli stroke of 8351 cubic inches, or 37 gallons. This would require 56 3-10 strokes per minuto to pump 3,000,000 gallons in 24 hours. Total piston travel per minute, 108 9-10 ft., or 84 45-100 ft. for each piston. By a similar calculation the non-con-densing ongine would discharge 4.740 cubic inches, or 20J- gallons por stroke, and 67 7-10 strokes per minute, for a displacement of 2,000,000 gallons in twentyfour hours, giving an aggregate piston travel per minute of 135 4-101't., or 67 7-10 ft. for each piston. Horso-power developed by compound engine when working under above conditions, 115; and by non-condensing engine, 77.