. The conquest of nature. .The operation of the fly-wheel largely compensatesthis difference of pressure in practise, but it would beobviously advantageous could the pressure be equalized;and, as just stated, the compoimd engine tends to pro-duce this result. The second, and perhaps the more important meritof the compound engine is, that it is found in practise tokeep the cylinders at a more imiform temperature. Amoments reflection makes it clear why this should bethe case, since in a single-cylinder engine the exhaustconnects with the cool condenser, whereas in the com-pound engine the exhaus
. The conquest of nature. .The operation of the fly-wheel largely compensatesthis difference of pressure in practise, but it would beobviously advantageous could the pressure be equalized;and, as just stated, the compoimd engine tends to pro-duce this result. The second, and perhaps the more important meritof the compound engine is, that it is found in practise tokeep the cylinders at a more imiform temperature. Amoments reflection makes it clear why this should bethe case, since in a single-cylinder engine the exhaustconnects with the cool condenser, whereas in the com-pound engine the exhaust from the first cylinder con-nects with the second cylinder at only slightly lowertemperature. In many modem engines a third cylinder and some-times even a fourth is added, constituting what arecalled respectively triple-expansion and quadruple-expansion engines. The triple-expansion system isvery generally employed, especially where it is peculiarlydesirable to economize fuel, as, for example, in the caseof ships. [ii8]. COMPOUND ENGINES. The lower figure illustrates the use of a modern compound engine, di-rectly operating the propeller shaft of a steamship. The middle figureshows a similarly direct apphcation of power to the axes of paddle upper figure shows the apphcation of power through a walking beamsimilar in principle to that of the original Newcomen and Watt engines. THE MASTER WORKER ROTARY ENGINES All these improvements, it will be observed, haveto do with details that do not greatly modify the steamengine from the original type. The cylinder with itsclosely fitting piston, as introduced in the Newcomenengine, is retained and constitutes the essential mechan-ism through which the energy of steam is transferredinto mechanical energy. But from a comparativelyremote period the idea has prevailed that it might bepossible to utilize a different principle; that, in short,if the steam instead of being made to press against apiston were allowed to rush against fa
Size: 1178px × 2122px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjec, booksubjectmachinery
