Wedge

(wědj.) [ From A. S. wæcg.] (Mech.) One of the six mechanical powers, reducible to the inclined plane, and governed by the same laws. It is used sometimes for raising bodies, but more usually for dividing or splitting them; in the former case, the W. is pushed under the body to be raised, but the effect is still that of an inclined plane, for the result is the same, and is estimated in the same way, whether the W. is pushed under the load, or the load is pushed over the W. When a W. is driven forward by percu ion, the power which acts upon it cannot be estimated with accuracy, on account of the friction, which is very considerable. This, however, is greatly diminished, for an instant, by the tremor caused by the blow. Cutting and piercing tools are generally constituted on the principle of the W.(Geom.) A prism with triangular bases. Spherical W., that portion of a globular body which is embraced between two planes intersecting a diameter. [s. 955]