Flywheel

(Mech.) A wheel with a heavy rim, placed on the shaft of any machinery put in motion by any irregular and intermitting force, for the purpose of rendering the motion equal and regular by means of its momentum. The rim of a fly-wheel, after a few revolutions, acquires a momentum sufficient to cause it to revolve with a velocity depending upon the resistance of the machinery. In all cases where a rotary motion is to be obtained from a reciprocating one by means of a crank, a fly-wheel is nece ary to continue the motion at those two points of the revolution in which the crank lies in the direction in which the moving force acts. The momentum acquired by the flywheel urges the crank forward in the direction in which it was previously moving, and continues the rotation, thus making the motion equal and uniform. F. M., abbreviation of FIELD-MARSHAL, q.v. Foa'ty, or Fo'ta, an island of Ireland, in Cork Harbor, abt. 6 m. N. of Queens town.