68 



the piston-rod to the water-plunger, which is attached to the other 

 end of the same rod, thus acting upon the water without the inter- 

 vention of a greater mass of metal than the strains absolutely require. 

 The engine being built so as to contain all these strains within itself, 

 the foundations are smaller, and much less expensive, than those re- 

 quired for other classes of engines." 



" The capacity of the engine is s\ich, that it will easily deliver into 

 the Reservoir one million gallons in twenty-four hours, through four 

 hundred and sixty-five feet of twelve-inch pipe, at a height of one 

 hundred and sixty feet." 



"It is about twenty-five horse-power. It has two double-acting 

 water-pistons ; and each piston-rod passes through a high pressure 

 into a low-pressure cylinder, in which the steam is first used at high 

 pressure and afterwards at low pressure. The steam cylinders are to 

 be protected by a steam jacket, and a covering of felt and black wal- 

 nut ; and are provided with balanced steam slide-valves. Steam- 

 water-pressure, and vacuum gauges are attached to the engine, and 

 there is also to be a counter to record the number of strokes." 



" There are four single-acting vertical air-pumps, worked by two 

 half-beams. The engine draws the water from the well through a 

 suction-pipe which delivers it into the water-cylinders. This suction- 

 pipe is fitted at its base with a ' foot-valve' to keep it always full 

 of water." 



The diameter of the suction-pipe is 12 inches. 



" " " " water-piston is 14 " 



Length of Stroke 17 " 



Diameter of the two high-pressure Cylinders 14 " 



'• " " low " " 24 " 



" The speed of the engine is from fifty to eighty strokes per minute, 

 as may be desired. The ordinary speed is about sixty strokes witli 

 the pressure of the steam forty pounds and the vacuum twenty-five 

 inches." 



BOILER. 



The Boiler is of the type known as the Horizontal Tubular. It is 

 fifteen feet long, four feet in diameter and contains thirty-nine tubes three 



