B = semi-rotary valve controlling admission of steam to A.
C = steam gland for piston rod connecting L and M.
D = Corliss-type air-inlet valves with semi-rotary motion. These valves are alternately open to the pipe system and the air cylinder E when the piston is travelling in one direction, and are closed (both to cylinder and air pipe) directly the piston reverses its travel.
E = cylinder of double-acting air pump.
F = valve gear for operating the Corliss valves, D this gear is driven by a pin out of centre on the flywheel.
G = cross-head and slide.
H = big-end bearing and crank.
I = flywheels on the main shaft.
J = eccentric and strap operating the valve, B, on the steam cylinder.
K = leather air-outlet valves held on two sides by metal strips. The leathers are opened by air pressure on the exhaust stroke, and are drawn on to their gridiron seatings during the inlet stroke.