The first waterwheel was a Greek mill built in the first century BC. This form utilised a horizontal wheel. In later times it became obsolete and vertical wheels came into use instead. These proved more practical as there is a greater allowance for the wheels to be enlarged in size and therefore generate more power.
Waterwheels operate by two main parts - the wheel and axle. Around the rim of the waterwheel are huge paddles, which are driven by the force of water striking them. This in turn produces a force on the shaft or axle at the centre.
Sometimes the waterwheel is used for grinding and milling purposes similar to a windmill, in other situations it may produce small amounts of electricity, mimicking the hydro-electric power station in a very basic way.
