Derqui, SANTIAGO

ab. 1810-1861. Pres. Argentina 1860. Derrick. 1. Floating crane with a central mast, standing upon a scow like hull, to which it is strongly braced; the jib extends horizontally at a considerable elevation, and equally on both sides of the mast. A counterbalance can be run out and in on the jib on one side to equalize the weight on the other side. It is used for putting boilers and machinery into ve els, 2. Hoisting machine for lifting weights, but without a buggy. for easy horizontal motion of the load. A winding barrel and gearing is at one end of a frame, and a pulley-block or purchase is hooked to the other end. The frame, being stood up in an inclined position and stayed with guy-ropes, is much used by builders to lay heavy stones. A hauling derrick is a simple windla frame. The quarry derrick has a mast and inclined boom; the boom can swing around the mast, but radial motion is given only by raising or lowering the end of the boom. In oil-well practice, the derrick carries the pulleys and apparatus for drilling the well. See CRANE.