Scientific American Supplement, No. 787, January 31, 1891

by means of the engagement of these tappets. The eccentric rod is fastened to a rocker arm having motion swinging about a pin or bearing in the governor slide, which may be raised or lowered by a cam operated by the governor. The cut off slide is of cylindrical shape and incloses a spring and dash pot with disks attached by means of which the valve is closed. The motion for operating the valves is relatively in the same direction, the cut off eccentric having the greatest throw and greater angular advance to cause it to open earlier and quickly before the main valve is ready to admit steam. The cut off eccentric rod swinging the rocker arm, the tappets thereon engage with those upon the cut off valve rod and open the passages to the main valve, and in their movement compress the spring in the main valve. According as the speed of the engine, the rock arm will be raised or lowered so that the tappets upon the eccentric rod may keep in engagement a shorter or longer time before they disengage, thus allowing th