Wedge

Wedge, one of the mechanical powers, in principle a modification of the Inclined Plane (q.v.). The power is applied to the back of the wedge by pressure or, more usually, by percussion. Familiar examples of its use are the splitting of wood, the fastening firmly of the handle of an axe, the raising of a ship in a dry-dock, &c. Axes, nails, plugs, planes, chisels, needles, and all sharp-pointed instruments are examples of the single wedge.