All three stations were based on standard Cornish pumps and were built essentially alike. One of them, Cruquius, is still in existence as a museum and is illustrated here.

There are eight pumps surrounding the central steam cylinder, but at Cruquius only seven were actually connected because the steam cylinder could not power all eight.

The cycle shown works as follows: First, steam is introduced into the center of the cylinder (at about 45 P.S.I.) The steam pushes the piston up, pushing the upper valves in the pumps down (two of eight are shown).

About halfway up the inlet steam valve is closed but steam continues to expand and push the piston up. It slows to a stop at the top of the cycle.

Next the exhaust valve is closed and the equilibrium valve is opened. Steam then flows around to the top of the piston and, with the aid of gravity, pushes down on the piston. The upper valves on the pumps move up and water is raised.

The equilibrium valve closes and the cycle repeats about seven times a minute.

(This is a 28-frame animation, converted to animated GIF format and then super-compressed for Internet transmission. The upstroke is slower than then downstroke intentionally, for historic accuracy. (Note: On some Internet browsers it may be displayed much less smoothly than the CD-ROM version, where the frames are timed to a thousandth of a second.))