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"The simplest idea of a crank is that of a handle to a wheel; its action is familiarly illustrated in the process of drawing water from a well: the bent handle attached to the wheel is first pushed out, then pulled in the opposite direction, and thus a continued rotatory motion is produced upon an axle. The application of this principle to the steam engine, and the variations of pressure on the crank of a steam enginre, may be conveniently illustrated by curves." —Comstock, 1850

Crank

"The simplest idea of a crank is that of a handle to a wheel; its action is familiarly illustrated in…