A loom is a device used to weave cloth and tapestry. The basic purpose of any loom is to hold the warp threads under tension to facilitate the interweaving of the weft threads. The precise shape of the loom and its mechanics may vary, but the basic function is the same. Etymology and usage The word "loom" derives from the Old English geloma, formed from ge- (perfective prefix) and loma, a root of unknown origin; the whole word geloma meant a utensil, tool, or machine of any kind. In 1404 "lome" was used to mean a machine to enable weaving thread into cloth. By 1838 "loom" had gained the additional meaning of a machine for interlacing thread. Weaving Loom Weaving is done by intersecting the longitudinal threads, the warp, i.e. the ones stretched on the loom (from the Proto-Indo-European *werp, "to bend") with the transverse threads, the weft, i.e. "that which is woven". The major components of the loom are the warp beam, heddles, harnesses or shafts (as few as two, four is common, sixteen not unheard of), shuttle, reed and takeup roll. In the loom, yarn processing includes shedding, picking, battening and taking-up operations. These are the principal motions. Shedding. Shedding is the raising of part of the warp yarn to form a shed (the vertical space between the raised and unraised warp yarns), through which the filling yarn, carried by the shuttle, can be inserted, forming the weft. On the modern loom, simple and intricate shedding operations are performed automatically by the heddle or heald frame, also known as a harness. This is a rectangular frame to which a series of wires, called heddles or healds, are attached. The yarns are passed through the eye holes of the heddles, which hang vertically from the harnesses. The weave pattern determines which harness controls which warp yarns, and the number of harnesses used depends on the complexity of the weave. Two common methods of controlling the heddles are dobbies and a Jacquard Head. Picking. As the harnesses raise the heddles or healds, which raise the warp yarns, the shed is created. The filling yarn is inserted through the shed by a small carrier device called a shuttle. The shuttle is normally pointed at each end to allow passage through the shed. In a traditional shuttle loom, the filling yarn is wound onto a quill, which in turn is mounted in