Governor (speed limiter)

   A governor is a device for regulating the speed of machinery. Watt, the inventor of the steam-engine, is responsible for the governor, as well as for many other of its accessories. The regulation of the speed is either by a throttle-valve in the steam-pipe or by controlling the supply of steam to the cylinder. In general the regulation is secured by centrifugal force due to increased speed causing balls to rise against gravity or against the force of springs. A decreased speed reverses the effect. Thus may the motion of the engine remain uniform with light or heavy load. Sometimes the governor is mounted upon the spoke of the flywheel, from which by a suitable gearing the supply of steam is increased or decreased.