“A movable pulley is one whos block is movable. One end of the cord is fastened to the beam, and the weight is sspended from the pulley, the other end of the cord being drawn by the application of a force P. A little consideration will show that if P moves through a certain distance, say 1 foot, W will move through half that distance, or 6 inches; hence, a pull of 1 pound at P will life 2 pounds at W.” — Hallock, 1905
