Throttle lever (Steam Engine), the hand lever by which a throttle valve is moved, especially in a locomotive.
Throttle valve (Steam Engine), a valve moved by hand or by a governor for regulating the supply of steam to the steam chest. In one form it consists of a disk turning on a transverse axis.
... "Throttle Valve" of the main steam-pipe, which, by means of the handle, is opened or closed at pleasure, the power of the steam and the progress of the carriage being thereby regulated from 1 to 10 or 20 miles ... — The Mirror of Literature, Amusement, and Instruction, Vol. 10, No. - 287, December 15, 1827 • Various