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Caution, the definition does not correspond to the given examples; either the definition, or the examples are inaccurate. The chain pump is type of a water pump in which several circular discs are positioned on an endless chain. One part of the chain dips into the water, and the chain runs through a tube, slightly bigger than the diameter of the discs. As the chain is drawn up the tube, water becomes trapped between the discs and is lifted to and discharged at the top. Chain pumps were used for centuries in the ancient Middle East, Europe, China, and ancient Egypt. ==In the Middle East and Europe== The earliest evidence for this device is in a Babylonian text from about 700 B.C. They were commonly powered by humans or animals.〔Joseph Needham, ''Science and Civilisation in China'' 4(2) (1965), p. 352.〕 The device then appeared in ancient Egypt from about 200 B.C., featuring a pair of gear-wheels.〔Donald Routledge Hill (1996), "Engineering", in Roshdi Rashed, ''Encyclopedia of the History of Arabic Science'', Vol. 3, pp. 751–795 ().〕 A version of the chain pump was used in Ancient Roman times, sometimes with pots fixed to the chain, which, as they passed over the top pulley, tipped the water out. Philo of Byzantium wrote of such a device in the 2nd century B.C.; the historian Vitruvius mentioned it around 30 B.C. Fragments of these buckets were found on the Roman barges of Lake Nemi.〔Needham, Volume 4, Part 2, p. 109.〕 Chain pumps were used in European mines during the Renaissance; mineralogist Georg Agricola illustrated them in his ''De re metallica'' (1556).〔G. Agricola, ''In Re Metallica'', 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「chain pump」の詳細全文を読む スポンサード リンク
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