Water Wheel

A water wheel is a machine that converts the kinetic energy of flowing or falling water into useful power, often as part of a watermill, consisting of a large wheel built of wood or metal with blades or buckets fixed around its rim to form the drive mechanism. It is fed from a mill pond formed by damming a stream, with a headrace channeling water to the wheel and a tailrace carrying it away afterward. Water wheels were used across the ancient Near East, the Hellenistic world, China, the Roman Empire and India, and continued through medieval Europe and the Islamic Golden Age, for tasks including milling flour, grinding pulp for paper, hammering wrought iron, machining, crushing ore and pounding fibre for cloth. In the mid to late 18th century the engineer John Smeaton's scientific study of the water wheel significantly increased its efficiency and helped power the Industrial Revolution, but starting in 1827 water wheels began to be displaced by the smaller, cheaper and more efficient turbine developed by Benoit Fourneyron, which could handle far higher heads than a practically sized wheel; water wheels nonetheless stayed in commercial use into the 20th century, and modern hydroelectric dams are their direct descendants.