Water Wheel

A water wheel is a machine that converts the energy of flowing or falling water into mechanical power, typically a large wheel fitted with blades or buckets around its rim that turn when struck by the water. Water wheels first appeared in the ancient Near East, including Egypt, by around the fourth century BC, and later spread across China, the Roman Empire and the Islamic world. They were used to grind grain, process pulp for papermaking, hammer metal and crush ore, powering much of Europe's economy through the medieval period and into the Industrial Revolution, before turbines began to displace them starting in 1827.