Wynfrid Laurence Henry Duckworth, 1911 Encyclopædia Britannica (1911)
“ In mechanics, a crank is a device by which reciprocating motion is converted into circular motion or vice versa, consisting of a crank-arm, one end of which is fastened rigidly at right angles to the rotating shaft or axis, while the other end bears a crank-pin, projecting from it at right angles and parallel to the shaft. ”
