Note: Do not rely on this information. It is very old.
Barkers Mill
Barker's Mill, an arrangement in which the reaction produced by water flowing from a vessel causes it to rotate. A hollow cylinder is supported vertically on a pivot so as to be capable of free rotation. Two hollow arms project from its lower end, and are provided with nozzles on opposite sides. When water is poured into the vessel at the top it flows out at these orifices, which are so arranged that the outflow of the water in one direction may cause the vessel to move in the opposite direction.