It was a popular machine for pumping water of medium differences in height that was used until recently. It consisted of a large rotating radial wheel with incorporated wooden containers which had an opening at the upper part for the inflow of abstractable water when they were at the lower point in their course and for the outflow of water when they were trapped at the higher point. The required energy for the movement of the wheel came from the tread of a worker on the incorporated steps in its circumference or a cooperating foot-powered wheel.

ΠΗΓΕΣ: Philon of Byzantium, Pneumatics, 61, Vitruvius, On architecture, X 4.