WHEEL, a circular frame or solid disc revolving on an axis, of which the function is to transmit or to modify motion. See MECHANICS. Vehicular wheels in the earliest times were circular discs, either cut out of solid pieces of wood or formed of sep arate planks of wood fastened together and then cut into a cir cular shape. Such may be still seen in use among primitive peoples to-day. The ordinary wheel consists of the nave (0. Eng. nafu;
cf. Ger. Nabe, allied with "navel"), the central portion or hub, through which the axle passes, the spokes, the radial bars inserted in the nave and reaching to the peripheral rim, the felloe or felly. (0. Eng. felge, Ger. Felge, properly that which fitted together, Teut. felhan, to fit together.) See also CARRIAGE ; CHARIOT ; MOTOR CAR ; MOTORCYCLE ; BI CYCLE.