Editing Chain pump

{{Short description|Type of water pump}}
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 [[Ancient Near East|Middle East]], [[Classical Antiquity|Europe]], and [[Ancient China|China]].

==In the Near East and Europe==
The earliest evidence for this device is in a [[Babylonia]]n text from about 700 B.C. They were commonly powered by humans or animals.<ref>[[Joseph Needham]], ''Science and Civilisation in China'' 4(2) (1965), p. 352.</ref> The device then appeared in [[ancient Egypt]] from about 200 B.C., featuring a pair of [[gear]]-wheels{{dubious|Sound exactly like the oldest saqiya/sakia occurrence in Ptolemaic Egypt. Most likely a confusion!|date=February 2015}}.<ref>[[Donald Routledge Hill]] (1996), "Engineering", in Roshdi Rashed, ''Encyclopedia of the History of Arabic Science'', Vol. 3, pp. 751–795 [771].</ref>

A version of the chain pump was used in [[ancient Greece]] and [[Ancient Rome|Rome]], sometimes with pots, or scoops fixed to the chain, which, as they passed over the top pulley, tipped the water out; a 2nd-century example is preserved in London.<ref>{{Citation|last1=Blair|first1=Ian|title=The technology of the 1st – and 2nd – century roman bucket chains from London: from excavation to reconstruction|date=2019-04-08|url=http://books.openedition.org/ausonius/10458|work=Aquam in altum exprimere : Les machines élévatrices d’eau dans l’Antiquité|pages=85–114|editor-last=Bouet|editor-first=Alain|series=Scripta Antiqua|place=Pessac|publisher=Ausonius Éditions|language=en|isbn=978-2-35613-295-6|access-date=2021-11-03|last2=Spain|first2=Robert|last3=Taylor|first3=Tony}}</ref> [[Philo of Byzantium]] wrote of such a device in the 2nd century B.C.;<ref>{{Cite web|title=The chained pump of Philon (''mangani'')|url=http://kotsanas.com/gb/exh.php?exhibit=1001005|access-date=2021-11-03|website=kotsanas.com|archive-date=2021-11-03|archive-url=https://web.archive.org/web/20211103013326/http://kotsanas.com/gb/exh.php?exhibit=1001005|url-status=dead}}</ref> the historian [[Vitruvius]] mentioned them around 30 B.C. Fragments of the cogs, crank, and discs, of a [[bilge pump]], from a 1st-century [[Nemi ships|Roman barge]], were unearthed at [[Lake Nemi]].<ref>{{Cite book|last=Robinson|first=Damian|url=https://www.researchgate.net/publication/236157707|title=Maritime Archaeology and AncientTrade in the Mediterranean|publisher=Oxford Centre for Maritime Archaeology Monograph|pages=43–44}}</ref><ref name="needham volume 4 part 2 109">Needham, Volume 4, Part 2, p. 109.</ref>

Chain pumps were used in European mines during the [[Renaissance]]; [[Mineralogy|mineralogist]] [[Georg Agricola]] illustrated them in his ''[[De re metallica]]'' (1556).<ref>G. Agricola, ''In Re Metallica'', <page needed>.</ref> Chain pumps were commonly used on naval vessels of the time to pump the bilges, and examples are known in the nineteenth century for low-lift irrigation.

==China==
[[Image:Tiangong Kaiwu Chain Pumps.jpg|thumb|right|Two types of [[Hydraulics|hydraulic]]-powered chain pump from the Chinese encyclopedia ''Tiangong Kaiwu'' (1637), written by [[Song Yingxing]].]]

Chain pumps were also used in ancient [[China]] from at least the 1st century A.D. In China, they were also called ''dragon backbones''.<ref name="needham volume 4 part 2 89 110">Needham, Volume 4, Part 2, 89, 110.</ref> One of the earliest accounts was a description by the Han dynasty [[Philosophy|philosopher]] [[Wang Chong]] (A.D. 27–97) around A.D. 80.<ref name="needham volume 4 part 2 344">Needham, Volume 4, Part 2, p. 344.</ref> Unlike those found in the West, chain pumps in China resembled the square-pallet type instead of the pear-shaped bucket{{dubious|pear-shaped buckets are more typical for sakias, disks or square pallets for chain pumps; check!|date=February 2015}}. Illustrations of such Chinese chain pumps show them drawing water up a slanted channel. These were sometimes powered by [[hydraulics]] of a rushing current against a horizontal [[water wheel]] acting against a vertical wheel,<ref name="needham volume 4 part 2 342 343">Needham, Volume 4, Part 2, pp. 342–343.</ref> and others by a horizontal mechanical wheel acting upon a vertical wheel that was pulled by the labor of [[ox]]en{{dubious|1-Syntax unclear, sounds like the oxen moving the vert. wheel, so what's the horiz. one's role? 2- If this corresponds to ill.: upper one is a water-wheel moving – what? Unclear. Maybe a pallets pump? Lower one shows no sign of a chain pump at all, rather a water-wheel moving a sakia-type chain of jugs. CHECK.|date=February 2015}}.<ref name="needham volume 6 part 2 500">Needham, Volume 6, Part 2, p. 500.</ref> There were also square-pallet chain pumps operated by pedals.<ref name="needham volume 4 part 2 340 341">Needham, Volume 4, Part 2, pp. 340–341.</ref>

From the 1st century onwards, chain pumps were widespread throughout the Chinese countryside.<ref name="needham volume 4 part 2 110">Needham, Volume 4, Part 2, p. 110.</ref> Chinese square-pallet chain pumps were used mostly for [[irrigation]], though they found use in [[public works]] as well. The infamous Eastern Han court [[eunuch]] [[Zhang Rang]] (d. A.D. 189) once ordered the engineer Bi Lan (畢嵐) to construct a series of square-pallet chain pumps outside the capital city [[Luoyang]].<ref name="needham volume 4 part 2 33">Needham, Volume 4, Part 2, p. 33.</ref> These chain pumps serviced the [[palace]]s and living quarters of the [[Luoyang]]; the water lifted by the chain pumps was brought in by a pipe system.<ref name="needham volume 4 part 2 33"/> [[Ma Jun (mechanical engineer)|Ma Jun]], the renowned [[Mechanical engineering|mechanical engineer]] of the [[Three Kingdoms]] era, also constructed a series of chain pumps for watering the palatial [[garden]]s of [[Cao Rui|Emperor Ming of Wei]] (226–239).<ref name="needham volume 4 part 2 40">Needham, Volume 4, Part 2, p. 40.</ref>

During the period of [[agricultural expansion]] in [[Song dynasty|Song China]] (10th–13th centuries CE), the technology of water-rising devices was improved. For some centuries they had been used for moving water for drainage or irrigation purposes. The simplest design, known as the counterbalanced bucket or 'swape' or 'well-sweep' was in common use at that time. A more complicated design, the 'square-pallet chain pump', was introduced several centuries before the growth in Song technology, but had not seen prior use for farming. They became more common around the end of the first millennium AD.<ref>{{cite book
|last=Elvin
|first=Mark
|title=The Patterns of the Chinese Past
|publisher=[[Stanford University Press]]
|year=1973
|isbn=0-8047-0876-2
|page=[https://archive.org/details/patternofchines00elvi/page/127 127]
|url-access=registration
|url=https://archive.org/details/patternofchines00elvi/page/127
}}</ref>

From the 13th century onwards, the Chinese also used [[windmill]]s (acquired from the Middle East) to power square-pallet chain pumps.<ref name="needham volume 4 part 2 558">Needham, Volume 4, Part 2, p. 558.</ref> Yet there were other types of chain pumps besides the square-pallet design. In [[Song Yingxing]]'s (1587–1666) encyclopedic book the ''Tiangong Kaiwu'' (1637), there is description and illustration of a [[Cylinder (geometry)|cylinder]] chain pump, powered by waterwheels and leading water up from the river to an elevated plain of agricultural crops.<ref name="song 15">Song, 15.</ref>

The contribution of chain pumps to agricultural growth during the Song was extolled by poets such as Li Chuquan (李处权) of the twelfth century. The Song government actively spread the technology, introducing pumping equipment and chain pumps to those areas as yet unfamiliar with the technique.<ref>{{cite book
|last=Elvin
|first=Mark
|title=The Patterns of the Chinese Past
|publisher=[[Stanford University Press]]
|year=1973
|isbn=0-8047-0876-2
|page=[https://archive.org/details/patternofchines00elvi/page/126 126]
|url-access=registration
|url=https://archive.org/details/patternofchines00elvi/page/126
}}</ref>

==See also==
*[[Airlift pump]]
*[[Chain drive]]
*[[Rope pump]]
*[[Sakia]]
*[[Waterladder pump]]

==Notes==
{{Reflist|colwidth=35em}}

==References==
{{Commons category|Chain pumps}}
* Needham, Joseph (1986).'' Science and Civilization in China: Volume 4, Physics and Physical Technology, Part 2, Mechanical Engineering''. Taipei: Caves Books, Ltd.
* Needham, Joseph (1986). ''Science and Civilization in China: Volume 6, Biology and Biological Technology, Part 2, Agriculture''. Taipei: Caves Books Ltd.
* Song, Yingxing, translated with preface by E-Tu Zen Sun and Shiou-Chuan Sun (1966). ''T'ien-Kung K'ai-Wu: Chinese Technology in the Seventeenth Century''. University Park: Pennsylvania State University Press.

{{DEFAULTSORT:Chain Pump}}
[[Category:Pumps]]
[[Category:Ancient Egyptian technology]]
[[Category:Ancient Roman technology]]
[[Category:Chinese inventions]]
[[Category:Greek inventions]]
[[Category:Hydraulics]]

[[nl:Touwpomp]]