History
Further information: WatermillIn water-raising devices rotary motion is typically more efficient than machines based on oscillating motion. In terms of power source, water wheels can be turned either by human or animal force or by the water current itself. Water wheels come in two basic designs, either equipped with a vertical or a horizontal axle. The latter type can be subdivided, depending on where the water hits the wheel paddles, into overshot, breastshot and undershot wheels. The two main functions of water wheels were historically water-lifting for irrigation purposes and milling, particularly of grain.
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Famous quotes containing the word history:
“It would be naive to think that peace and justice can be achieved easily. No set of rules or study of history will automatically resolve the problems.... However, with faith and perseverance,... complex problems in the past have been resolved in our search for justice and peace. They can be resolved in the future, provided, of course, that we can think of five new ways to measure the height of a tall building by using a barometer.”
—Jimmy Carter (James Earl Carter, Jr.)
“A country grows in history not only because of the heroism of its troops on the field of battle, it grows also when it turns to justice and to right for the conservation of its interests.”
—Aristide Briand (18621932)
“The history of mankind interests us only as it exhibits a steady gain of truth and right, in the incessant conflict which it records between the material and the moral nature.”
—Ralph Waldo Emerson (18031882)