A history of the growth of the steam-engine . its details. Steam-pressures are carried which werenever reached during the preceding period, and, by carefuladjustment of well-set and well-proportioned valves andgearing, the engine has been made to work rather more rap-idly, and to do considerably more work. It still remains,however, a large, costly, and awkward contrivance, requir-ing expensive foundations, and demanding exceptional care,skill, and experience in management. It is gradually goingout of use. This engine, as now constructed by goodbuilders, is shown in section in Fig. 101. A compa
A history of the growth of the steam-engine . its details. Steam-pressures are carried which werenever reached during the preceding period, and, by carefuladjustment of well-set and well-proportioned valves andgearing, the engine has been made to work rather more rap-idly, and to do considerably more work. It still remains,however, a large, costly, and awkward contrivance, requir-ing expensive foundations, and demanding exceptional care,skill, and experience in management. It is gradually goingout of use. This engine, as now constructed by goodbuilders, is shown in section in Fig. 101. A comparison with the Watt engine of a century earlierwill at once enable any one to appreciate the extent towhich changes may be made in perfecting a machine, even STATIONARY ENGINES. 329 after it has become complete, so far as supplying it withall essential parts can complete it. In the figure, A is the cylinder, taking steam from theboiler through the steam-passage, Ml The steam is firstadmitted above the piston, J3, driving it rapidly downward. Fio. 101.—Comish Pomping-Engine, 1878. Section. and raising the pump-rod, M At an early period in thestroke the admission of steam is checked by the suddenclosing of the induction-valve at M, and the stroke is com-pleted under the action of expanding steam assisted by theinertia of the heavy parts already in motion. The neces-sary weight and inertia is afforded, in many cases, wherethe engine is applied to the pumping of deep mines, by the 330 THE STEAM-ENGINE OF TO-DAY. immensely long and heavy pump-rods. Where this weightis too great, it is counterbalanced, and where too small,weights are added. When the stroke is completed, the equilibrium valve is opened, and the steam passes fromabove to the space below the piston, and an equilibrium ofpressure being thus produced, the pump-rods descend, forc-ing the water from the pumps and raising the absence of the crank, or other device which might de-termine absolutely the lengt
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Keywords: ., bookcentury1800, bookdecade1870, bookidc, booksubjectsteamengines
