A Persian Wheel is a machine to lift water from a moving water source such as river or large spring. It is a mechanical device with a large wheel which moves by the force of the rush of water waves. The wheel has a lot of buckets which get filled up when they go into water. As the wheel moves, the buckets pour water into a shaft which then flows into channels. These were first developed in Mesopotamia (now Iraq) 3,500 year ago and were copied by Egyptian and were further developed in ancient Iran. From here they were carried to Spain and Syria. In India they came to be known as ‘Rahat’ but were mostly driven by oxen. They were in use till the early part of the last century. But with arrival of electricity operated pumps, they went out of use.
The main difficulty with Persian wheels or ‘Rahat’ was that they could be moved only by rushing water. When water level went down, they will cease to work.