Plate from 18th century encyclopedia showing illustrations of various mechanical principles and devices, and diagrams of mechanical forces. The main illustration shows the cogwheels of a water powered mill. In the Barker's mill water is delivered to a top of a vertical cylinder at the bottom of which there is a rotor with specially bent pipes with nozzles. Due to the hydrostatic pressure the water is ejected from the nozzles causing the rotation of the rotor. The useful torque is transferred to a powered device through a belt and pulley system. At the bottom are motion diagrams.