Water wheel

A water wheel is a <a href="/facts/Machine/Dq1W2kwI">machine</a> for converting the <a href="/facts/Kinetic_energy/aJRxUd4p">kinetic energy</a> of flowing or falling <a href="/facts/Water/0lkXnJPK">water</a> into useful forms of power, often in a <a href="/facts/Watermill/UTvzQY8S">watermill</a>. A water wheel consists of a large wheel (usually constructed from wood or metal), with numerous <a href="/facts/Blade/yxqtx5hq">blades</a> or <a href="/facts/Bucket/uh8M4AFD">buckets</a> attached to the outer rim forming the drive mechanism. Water wheels were still in commercial use well into the 20th century, although they are no longer in common use today. Water wheels are used for milling flour in <a href="/facts/Gristmill/TP4qMmSr">gristmills</a>, grinding wood into pulp for <a href="/facts/Papermaking/XPErFtEk">papermaking</a>, hammering <a href="/facts/Wrought_iron/zynpjrIv">wrought iron</a>, machining, ore crushing and pounding fibre for use in the manufacture of <a href="/facts/Cloth/PJrVeM5S">cloth</a>.
Some water wheels are fed by water from a <a href="/facts/Mill_pond/D3xgMds7">mill pond</a>, which is formed when a flowing stream is <a href="/facts/Dam/9GuSN9HB">dammed</a>. A channel for the water flowing to or from a water wheel is called a <a href="/facts/Mill_race/5qERs27W">mill race</a>. The race bringing water from the mill pond to the water wheel is a headrace; the one carrying water after it has left the wheel is commonly referred to as a tailrace.
Waterwheels were used for various purposes from things such as <a href="/facts/History_of_agriculture/N7bJ4tdM">agriculture</a> to <a href="/facts/History_of_ferrous_metallurgy/XpwtCB0X">metallurgy</a> in ancient civilizations spanning the <a href="/facts/Near_East/gD1vyGQI">Near East</a>, <a href="/facts/Hellenistic_world/q6BgQsaF">Hellenistic world</a>, <a href="/facts/History_of_China/TNqRSvQ4">China</a>, <a href="/facts/Roman_Empire/l4E1aUuV">Roman Empire</a> and <a href="/facts/History_of_India/ntYkAYDQ">India</a>. Waterwheels saw continued use in the <a href="/facts/Post-classical_history/CB2mY6tf">post-classical age</a>, like in <a href="/facts/Middle_Ages/RqzEKB9v">medieval Europe</a> and the <a href="/facts/Islamic_Golden_Age/yAeG2rBA">Islamic Golden Age</a>, but also elsewhere. In the mid- to late 18th century <a href="/facts/John_Smeaton/ylvEax8g">John Smeaton</a>'s scientific investigation of the water wheel led to significant increases in efficiency, supplying much-needed power for the <a href="/facts/Industrial_Revolution/B6E3Fasm">Industrial Revolution</a>. Water wheels began being displaced by the smaller, less expensive and more efficient <a href="/facts/Turbine/gqosKCkI">turbine</a>, developed by <a href="/facts/Beno%25C3%25AEt_Fourneyron/cYlddg3o">Benoît Fourneyron</a>, beginning with his first model in 1827. Turbines are capable of handling high <a href="/facts/Hydrostatic_head/bm5I62Jm">heads</a>, or <a href="/facts/Elevation/h2d0u9nd">elevations</a>, that exceed the capability of practical-sized waterwheels.
The main difficulty of water wheels is their dependence on flowing water, which limits where they can be located. Modern <a href="/facts/Hydroelectricity/zEeJIK2B">hydroelectric dams</a> can be viewed as the descendants of the water wheel, as they too take advantage of the movement of water downhill.

Water wheel open-in-new

Water wheel