A history of the growth of the steam-engine . tes handles notshown, -ffis the exhaust-pipe leading to the condenser. Vis the engine feed-pump rod, and JC the great rod carryingthe pump-buckets at the bottom of the shaft. The cocks c and a being open and b and d shut, thesteam passes from the boiler into the upper part of thesteam-cylinder, £; and the communication between thelower part of B and the top of A is also open. Beforestarting, steam being shut off from the engine, the greatweight of the pump-rod, -3^ causes that end of the beam topreponderate, the pistons standing, as shown, at the t
A history of the growth of the steam-engine . tes handles notshown, -ffis the exhaust-pipe leading to the condenser. Vis the engine feed-pump rod, and JC the great rod carryingthe pump-buckets at the bottom of the shaft. The cocks c and a being open and b and d shut, thesteam passes from the boiler into the upper part of thesteam-cylinder, £; and the communication between thelower part of B and the top of A is also open. Beforestarting, steam being shut off from the engine, the greatweight of the pump-rod, -3^ causes that end of the beam topreponderate, the pistons standing, as shown, at the top oftheir respective steam-cylinders. The engine being freed from all air by opening all the 136 THE DEVELOPMENT OF THE MODERN STEAM-ENGINE. valves and permitting the steam to drive it through the en-gine and out of the condenser through the snifting-valve,0, the valves h and d are closed, and the coot in the ex-haust-pipe opened. The steam beneath the piston of the large cylinder isimmediately condensed, and the pressure on the upper side. Fia. 37.—Hornblowers Compound Engine, 1781. of that piston causes it to descend, carrying that end of thebeam with it, and raising the opposite end with the pump-rods and their attachments. At the same time, the steamfrom the lower end of the small high-pressure cylinder beinglet into the upper end of the larger cylinder, the completionof the stroke finds a cylinder full of steam transferred fromthe one to the other with corresponding increase of volumeand decrease of pressure. While expanding and diminish-ing in pressure as it passes from the smaller into the larger THE CONTEMPORARIES OF JAMES WATT. I37 cylinder, this charge of steam gradually resists less and lessthe pressure of the steam from the boiler on the upper sideof the piston of the small cylinder, B, and the net result isthe movement of the engine by pressures exerted on theupper sides of both pistons and against pressures of less in-tensity on the under sides of both. The pr
Size: 1420px × 1760px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, bookidc, booksubjectsteamengines
