Overshot Water Wheel

An overshot water wheel is a water wheel turned mainly by the weight of water falling into buckets built around its rim from above, rather than by the push of water flowing past its base. Because it captures both the weight of the falling water and some of its speed, it is generally more efficient than an undershot wheel, and was favored wherever a mill had enough fall in the stream to feed water in at or near the top of the wheel. Overshot wheels were common at gristmills and early factories in Europe and North America from the medieval period through the Industrial Revolution, before being displaced by water turbines and then electric motors.