Waterwheel

A waterwheel is a machine that converts the kinetic energy of flowing or falling water into useful mechanical power, typically to drive a mill, using a large wheel fitted with blades or buckets around its rim. It first appeared in the ancient Near East, in Egypt, in the 4th century BC, where it was used to lift water for irrigation. Scholars believe the earliest water wheels were norias, evolving by the 2nd century BC into the vertical watermill used in Syria and Asia Minor, from where the technology spread to Greece, the Roman Empire, China and the Islamic world.