It was a popular machine for pumping water of medium difference in altitude that was used until recently. It consisted of a large rotating radial wheel with incorporated wooden containers that had an opening at the side upper part for the inflow of pumped water when they were at the lower point in their course and for the outflow of trapped water when they were 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.