Crane

—A machine for hoisting and lowering heavy weights. It consists of a vertical post or frame, which is rotatable on its axis, and a jib or projecting arm over which the chain or rope pa es on its way from the winch at the foot of the post to the load to be lifted. Cranes are arranged to be operated by hand, steam, hydraulic power or electricity; they may also be operated by means of endle ropes or shafting and worm gearing from another source of power.