Persian wheel
Device to lift water, particularly for agricultural purposes. It consists of an endless chain of buckets, typically with an individual capacity of 8-15 litres mounted on a drum and submerged in water to the required depth. The drum is connected to a toothed wheel held in a vertical plane by a long shaft usually kept below ground level. The vertical toothed wheel is geared with a large toothed horizontal wheel connected to a horizontal beam. This beam is yoked to a pair of animals. The animals move in a circle to turn the drum and raise the water.