Editing Vacuum pump (section)

== History ==
===Early pumps===

The predecessor to the vacuum pump was the suction pump. Dual-action suction pumps were found in the city of [[Pompeii]].<ref>{{cite web|url=http://www.imss.fi.it/pompei/tecnica/epompa.html|title=Pompeii: Technology: Working models: IMSS}}</ref> Arabic engineer [[Al-Jazari]] later described dual-action suction pumps as part of water-raising machines in the 13th century. He also said that a suction pump was used in [[siphons]] to discharge [[Greek fire]].<ref name="Hill" /> The suction pump later appeared in medieval Europe from the 15th century.<ref name="Hill">[[Donald Routledge Hill]] (1996), ''A History of Engineering in Classical and Medieval Times'', [[Routledge]], pp. 143 & 150-2</ref><ref name=Hill2>[[Donald Routledge Hill]], "Mechanical Engineering in the Medieval Near East", ''Scientific American'', May 1991, pp. 64-69 ([[cf.]] [[Donald Routledge Hill]], [https://web.archive.org/web/20110101193750/http://home.swipnet.se/islam/articles/HistoryofSciences.htm Mechanical Engineering])</ref><ref>{{cite web|author=Ahmad Y Hassan |title=The Origin of the Suction Pump: Al-Jazari 1206 A.D |url=http://www.history-science-technology.com/Notes/Notes%202.htm |access-date=2008-07-16 |author-link=Ahmad Y Hassan |url-status=dead |archive-url=https://web.archive.org/web/20080226102543/http://www.history-science-technology.com/Notes/Notes%202.htm |archive-date=February 26, 2008 }}</ref>

[[File:Molchanova by levitskiy.jpg|thumb|Student of [[Smolny Institute]] Catherine Molchanova with vacuum pump, by [[Dmitry Levitzky]], 1776]]
By the 17th century, water pump designs had improved to the point that they produced measurable vacuums, but this was not immediately understood. What was known was that suction pumps could not pull water beyond a certain height: 18 Florentine yards according to a measurement taken around 1635, or about {{Convert|34|ft|m}}.<ref name=":0">{{cite book|last=Gillispie|first=Charles Coulston|url=https://archive.org/details/edgeofobjectivit00char|title=The Edge of Objectivity: An Essay in the History of Scientific Ideas|publisher=Princeton University Press|year=1960|isbn=0-691-02350-6|location=Princeton, NJ|pages=99–100|author-link=Charles Coulston Gillispie}}</ref> This limit was a concern in irrigation projects, mine drainage, and decorative water fountains planned by the Duke of [[Tuscany]], so the duke commissioned [[Galileo Galilei]] to investigate the problem. Galileo suggested, incorrectly, in his ''[[Two New Sciences]]'' (1638) that the column of a water pump will break of its own weight when the water has been lifted to 34 feet.<ref name=":0" /> Other scientists took up the challenge, including [[Gasparo Berti]], who replicated it by building the first water barometer in Rome in 1639.<ref>{{cite web |url=http://www.denmark.com.au/en/Worlds+Largest+Barometer/default.htm |archive-url=https://web.archive.org/web/20080216140317/http://www.denmark.com.au/en/Worlds+Largest+Barometer/default.htm |archive-date=2008-02-16 |title=The World's Largest Barometer |access-date=2008-04-30 }}</ref> Berti's barometer produced a vacuum above the water column, but he could not explain it. A breakthrough was made by Galileo's student [[Evangelista Torricelli]] in 1643. Building upon Galileo's notes, he built the first [[Mercury (element)|mercury]] [[barometer]] and wrote a convincing argument that the space at the top was a vacuum. The height of the column was then limited to the maximum weight that atmospheric pressure could support; this is the limiting height of a suction pump.{{Sfn|Calvert|2000|loc="Maximum height to which water can be raised by a suction pump"}}

In 1650, [[Otto von Guericke]] invented the first vacuum pump.<ref>{{Cite journal|last=Harsch|first=Viktor|date=November 2007|title=Otto von Gericke (1602–1686) and his pioneering vacuum experiments|url=https://pubmed.ncbi.nlm.nih.gov/18018443/|journal=Aviation, Space, and Environmental Medicine|volume=78|issue=11|pages=1075–1077|doi=10.3357/asem.2159.2007|issn=0095-6562|pmid=18018443}}</ref> Four years later, he conducted his famous [[Magdeburg hemispheres]] experiment, showing that teams of horses could not separate two hemispheres from which the air had been evacuated. [[Robert Boyle]] improved Guericke's design and conducted experiments on the properties of vacuum. [[Robert Hooke]] also helped Boyle produce an air pump that helped to produce the vacuum.

By 1709, Francis Hauksbee improved on the design further with his two-cylinder pump, where two pistons worked via a rack-and-pinion design that reportedly "gave a vacuum within about one inch of mercury of perfect."<ref name=":1">{{Cite journal |last=da C. Andrade |first=E.N. |year=1953 |title=The history of the vacuum pump |url=https://linkinghub.elsevier.com/retrieve/pii/0042207X5990555X |journal=Vacuum |language=en |volume=9 |issue=1 |pages=41–47 |doi=10.1016/0042-207X(59)90555-X}}</ref> This design remained popular and only slightly changed until well into the nineteenth century.<ref name=":1" />

===19th century===
[[Image:HiVacuumApparatus-Tesla.png|thumb|333px|Tesla's vacuum apparatus, published in 1892]]
[[Heinrich Geissler]] invented the mercury displacement pump in 1855<ref name=":1" /> and achieved a record vacuum of about 10&nbsp;Pa (0.1 [[Torr]]). A number of electrical properties become observable at this vacuum level, and this renewed interest in vacuum. This, in turn, led to the development of the [[vacuum tube]].<ref>{{Cite book |url=https://books.google.com/books?id=VHFyngmO95YC&pg=PA7 |title=History of electron tubes |date=1994 |publisher=Ohmsha |isbn=90-5199-145-2 |editor-last=Okamura, S. |location=Tokyo |pages=7–11 |oclc=30995577}}</ref> The [[Sprengel pump]] was a widely used vacuum producer of this time.<ref name=":1" />

===20th century===
The early 20th century saw the invention of many types of vacuum pump, including the [[molecular drag pump]],<ref name=":1" /> the [[diffusion pump]],<ref>{{Cite book |last=Dayton, B.B. |url=https://www.worldcat.org/oclc/28587335 |title=Vacuum science and technology : pioneers of the 20th century : history of vacuum science and technology volume 2 |date=1994 |publisher=AIP Press for the American Vacuum Society |isbn=1-56396-248-9 |editor-last=Redhead, P.A. |location=New York, NY |pages=107–13 |chapter=History of the Development of Fusion Pumps |oclc=28587335}}</ref> and the [[turbomolecular pump]].<ref>{{Cite book |url=https://www.worldcat.org/oclc/28587335 |title=Vacuum science and technology : pioneers of the 20th century : history of vacuum science and technology volume 2 |date=1994 |publisher=AIP Press for the American Vacuum Society |isbn=1-56396-248-9 |editor-last=Redhead, P.A. |location=New York, NY |pages=96 |oclc=28587335}}</ref>