Editing Hydraulics

{{Short description|Applied engineering involving liquids}}
{{redirect|Hydraulic|other uses|Hydraulic (disambiguation)}}
{{For|the mechanical technology|hydraulic machinery}}
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[[File:Hydraulics and other studies (en).svg|thumb|Hydraulics and other studies<ref>{{Citation|author=NEZU Iehisa|year=1995|title=Suirigaku, Ryutai-rikigaku|publisher=Asakurae Shoten|isbn=978-4-254-26135-6|page=17|postscript=.}}</ref>]]
[[File:Open Channel.png|thumb|''An open channel'', with a uniform depth. ''Open-channel hydraulics]][[File: Table of Hydraulics and Hydrostatics, Cyclopaedia, Volume 1.jpg|thumb|Illustration of hydraulic and hydrostatic, from the "Table of Hydraulics and Hydrostatics", from ''[[Cyclopædia, or an Universal Dictionary of Arts and Sciences]]'', edited by [[Ephraim Chambers]], 1728, Vol. 1]]

'''Hydraulics''' ({{etymology|grc|''{{Wikt-lang|grc|ὕδωρ}}'' ({{grc-transl|ὕδωρ}})|[[water]]||''{{Wikt-lang|grc|αὐλός}}'' ({{grc-transl|αὐλός}})|[[plumbing|pipe]]}})<ref>{{cite EB1911 |wstitle=Hydraulics |volume=14 |page=35}}</ref> is a technology and [[applied science]] using [[engineering]], [[chemistry]], and other sciences involving the mechanical properties and use of [[liquid]]s. At a very basic level, hydraulics is the liquid counterpart of [[pneumatics]], which concerns [[gas]]es. [[Fluid mechanics]] provides the theoretical foundation for hydraulics, which focuses on applied engineering using the properties of fluids. In its [[fluid power]] applications, hydraulics is used for the generation, control, and transmission of [[Power (physics)|power]] by the use of [[pressure|pressurized]] liquids. Hydraulic topics range through some parts of science and most of engineering modules, and they cover concepts such as pipe [[Volumetric flow rate|flow]], [[dam]] design, [[fluidics]], and fluid control circuitry. The principles of hydraulics are in use naturally in the human body within the [[vascular system]] and [[erectile tissue]].<ref>{{cite web|url=http://www.industrialoutpost.com/human-circulatory-system-heart-modern-hydraulic/|archive-url=https://web.archive.org/web/20170501112640/http://www.industrialoutpost.com/human-circulatory-system-heart-modern-hydraulic/|url-status=dead|archive-date=1 May 2017|title=The Circulatory System: The Hydraulics of the Human Heart|date=1 May 2017|access-date=19 March 2019}}</ref><ref>{{cite journal |last1=Meldrum |first1=David R. |last2=Burnett |first2=Arthur L. |last3=Dorey |first3=Grace |last4=Esposito |first4=Katherine |last5=Ignarro |first5=Louis J. |title=Erectile Hydraulics: Maximizing Inflow While Minimizing Outflow |journal=The Journal of Sexual Medicine |volume=11 |issue=5 |pages=1208–20 |year=2014 |pmid=24521101 |doi=10.1111/jsm.12457 }}</ref>

''Free surface hydraulics'' is the branch of hydraulics dealing with [[free surface]] flow, such as occurring in [[river]]s, [[canal]]s, [[lake]]s, [[estuary|estuaries]], and [[sea]]s. Its sub-field [[open-channel flow]] studies the flow in open [[channel (geography)|channels]].

== Early history ==
[[File:Tuebingen-gerstenmuehle.jpg|thumb|200px|Waterwheels]]
{{further|Timeline of fluid and continuum mechanics}}

Early uses of water power date back to [[Mesopotamia]] and [[ancient Egypt]], where [[irrigation]] has been used since the 6th millennium BC and [[water clock]]s had been used since the early 2nd millennium BC. Other early examples of [[water]] power include the [[Qanat]] system in ancient Persia and the [[Turpan water system]] in ancient Central Asia.

=== Persian Empire and Urartu ===

In the [[Persian Empire]] or previous entities in Persia, the [[Persians]] constructed an intricate system of water mills, canals and dams known as the [[Shushtar Historical Hydraulic System]]. The project, commenced by [[Achaemenid Empire|Achaemenid]] king [[Darius I|Darius the Great]] and finished by a group of Roman engineers captured by Sassanian king [[Shapur I]],<ref name="auto">{{cite web|url=https://whc.unesco.org/en/list/1315|title=Shushtar Historical Hydraulic System|last=Centre|first=UNESCO World Heritage|website=Whc.unesco.org|language=en|access-date=2018-09-01}}</ref> has been referred to by [[UNESCO]] as "a masterpiece of creative genius".<ref name="auto"/> They were also the inventors<ref>{{Cite book|title=The qanats of Iran|last=Goldsmith|first=Edward|year=2012}}</ref> of the [[Qanat]], an underground aqueduct, around the 9th century BC.<ref name=":0">{{Cite journal |last=Lombard |first=Pierre |date=1991 |title=Du rythme naturel au rythme humain : vie et mort d'une technique traditionnelle, le qanat |url=https://www.persee.fr/doc/mom_0766-0510_1991_sem_20_1_1776 |journal=MOM Éditions |volume=20 |issue=1 |pages=69–86}}</ref> Several of Iran's large, ancient gardens were irrigated thanks to Qanats.<ref>{{Cite news|url=http://www.edwardgoldsmith.org/1031/the-qanats-of-iran/|archive-url=https://archive.today/20130414210607/http://www.edwardgoldsmith.org/1031/the-qanats-of-iran/|url-status=dead|archive-date=2013-04-14|title=The qanats of Iran · Edward Goldsmith|date=2013-04-14|work=archive.is|access-date=2018-09-01}}</ref>

The Qanat spread to neighboring areas, including the [[Armenian highlands]]. There, starting in the early 8th century BC, the [[Urartu|Kingdom of Urartu]] undertook significant hydraulic works, such as the [[Menua Canal|Menua canal]].<ref name=":2">{{Cite book |last=Viollet |first=Pierre-Louis |url=https://books.google.com/books?id=j5xTES80ExIC |title=L'hydraulique dans les civilisations anciennes: 5000 ans d'histoire |date=2004 |publisher=Presses des Ponts |isbn=978-2-85978-397-6 |language=fr}}</ref><ref name=":0" /><ref name=":5">{{Cite journal |last=Burney |first=Charles |date=1972 |title=Urartian Irrigation Works. |url=https://www.cambridge.org/core/product/identifier/S0066154600003422/type/journal_article |journal=Anatolian Studies |language=en |volume=22 |pages=179–186 |doi=10.2307/3642562 |jstor=3642562 |s2cid=131657710 |issn=0066-1546}}</ref>

The earliest evidence of [[water wheel]]s and [[watermill]]s date back to the [[ancient Near East]] in the 4th century BC,<ref>Terry S. Reynolds, ''Stronger than a Hundred Men: A History of the Vertical Water Wheel'', JHU Press, 2002 {{ISBN|978-0-8018-7248-8}}, p. 14</ref> specifically in the Persian Empire before 350&nbsp;BCE, in the regions of [[Iraq]], [[Iran]],<ref>{{cite book |last1=Selin |first1=Helaine |title=Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures |date=2013 |publisher=[[Springer Science & Business Media]] |isbn=978-94-017-1416-7 |page=282 |url=https://books.google.com/books?id=GzjpCAAAQBAJ&pg=PA282}}</ref> and [[Egypt]].<ref>{{cite journal|title=Evolution of Water Lifting Devices (Pumps) over the Centuries Worldwide|author1=Stavros I. Yannopoulos|author2=Gerasimos Lyberatos|author3=Nicolaos Theodossiou|author4=Wang Li|author5=Mohammad Valipour|author6=Aldo Tamburrino|author7=Andreas N. Angelakis|author7-link=Andreas N. Angelakis|journal=Water|year=2015|volume=7|issue=9|pages=5031–5060|publisher=[[MDPI]]|doi=10.3390/w7095031|doi-access=free|bibcode=2015Water...7.5031Y }}</ref>

=== China ===

In [[ancient China]] there was [[Sunshu Ao]] (6th century BC), [[Ximen Bao]] (5th century BC), [[Du Shi]] (circa 31 AD), [[Zhang Heng]] (78 – 139 AD), and [[Ma Jun (mechanical engineer)|Ma Jun]] (200 – 265 AD), while medieval China had [[Su Song]] (1020 – 1101 AD) and [[Shen Kuo]] (1031–1095). Du Shi employed a [[waterwheel]] to power the [[bellows]] of a [[blast furnace]] producing [[cast iron]]. Zhang Heng was the first to employ hydraulics to provide motive power in rotating an [[armillary sphere]] for [[Chinese astronomy|astronomical observation]].<ref>{{Cite book|title=Origins of Chinese science and technology|author=Fu, Chunjiang|last2=Liping.|first2=Yang|last3=N.|first3=Han, Y.|last4=Editorial.|first4=Asiapac|date=2006|publisher=Asiapac|isbn=978-981-229-376-3|oclc=71370433}}</ref><ref>{{cite web |url=https://www.loc.gov/item/2021666393 |title=Armillary Sphere |publisher=[[Library of Congress]] |date= |accessdate=2022-07-10}}</ref>

=== Sri Lanka ===
[[File:Sigiriya moat and garden2.jpg|thumb|right|250px|Moat and gardens at [[Sigiriya]]]]

In ancient Sri Lanka, hydraulics were widely used in the ancient kingdoms of [[Anuradhapura]] and [[Polonnaruwa]].<ref>{{cite web |url=http://www.marines.mil/news/publications/Documents/Sri%20Lanka%20Study_1.pdf |title=SriLanka-A Country study |year=1990 |publisher=USA Government, Department of Army|access-date=9 November 2011|archive-url=https://web.archive.org/web/20120905131619/http://www.marines.mil/news/publications/Documents/Sri%20Lanka%20Study_1.pdf|archive-date=5 September 2012}}</ref> The discovery of the principle of the valve tower, or valve pit, (Bisokotuwa in Sinhalese) for regulating the escape of water is credited to ingenuity more than 2,000 years ago.<ref>{{cite web|url=http://asia.isp.msu.edu/wbwoa/south_asia/sri_lanka/history.htm|title=SriLanka – History|publisher=Asian Studies Center, Michigan State University|access-date=9 November 2011|url-status=dead|archive-url=https://web.archive.org/web/20111228234152/http://asia.isp.msu.edu/wbwoa/south_asia/sri_lanka/history.htm|archive-date=28 December 2011}}</ref> By the first century AD, several large-scale irrigation works had been completed.<ref>{{cite web|url=http://www.shsu.edu/~his_ncp/SriLanka.html|title=Traditional SriLanka or Ceylon|publisher=Sam Houston State University|access-date=9 November 2011|url-status=dead|archive-url=https://web.archive.org/web/20110927020022/http://www.shsu.edu/~his_ncp/SriLanka.html|archive-date=27 September 2011}}</ref> Macro- and micro-hydraulics to provide for domestic horticultural and agricultural needs, surface drainage and erosion control, ornamental and recreational water courses and retaining structures and also cooling systems were in place in [[Sigiriya]], Sri Lanka. The coral on the massive rock at the site includes [[cistern]]s for collecting water.  Large ancient reservoirs of Sri Lanka are Kalawewa (King Dhatusena), Parakrama Samudra (King Parakrama Bahu), Tisa Wewa (King Dutugamunu), Minneriya (King Mahasen)

=== Greco-Roman world ===

In [[Ancient Greece]], the Greeks constructed sophisticated water and hydraulic power systems. An example is a construction by [[Eupalinos]], under a public contract, of a watering channel for [[Samos]], the [[Tunnel of Eupalinos]]. An early example of the usage of hydraulic wheel, probably the earliest in Europe, is the Perachora wheel (3rd century BC).<ref>{{cite journal |last1=Tomlinson |first1=R. A. |title=The Perachora Waterworks: Addenda |journal=The Annual of the British School at Athens |volume=71 |year=2013 |pages=147–8 |jstor=30103359 |doi=10.1017/S0068245400005864 |s2cid=129173283 }}</ref>

In [[Greco-Roman Egypt]], the construction of the first hydraulic machine [[automata]] by [[Ctesibius]] (flourished c. 270 BC) and [[Hero of Alexandria]] (c. 10 – 80 AD) is notable. Hero describes several working machines using hydraulic power, such as the [[force pump]], which is known from many Roman sites as having been used for raising water and in fire engines.<ref>Museum, Victoria and Albert. "Catalogue of the mechanical engineering collection in the Science Division of the Victoria and Albert Museum, South Kensington, with descriptive and historical notes." Ulan Press. 2012.</ref>

[[File:Segovia Aqueduct.JPG|thumb|250px|[[Aqueduct of Segovia]], a 1st-century AD masterpiece]]

In the [[Roman Empire]], different hydraulic applications were developed, including public water supplies, innumerable [[Aqueduct (water supply)|aqueduct]]s, power using watermills and [[hydraulic mining]]. They were among the first to make use of the [[siphon]] to carry water across valleys, and used [[hushing]] on a large scale to prospect for and then extract metal [[ore]]s. They used [[lead]] widely in [[plumbing]] systems for domestic and public supply, such as feeding [[thermae]].{{citation needed|date=November 2016}}

Hydraulic mining was used in the gold-fields of northern Spain, which was conquered by [[Augustus]] in 25 BC. The alluvial [[gold-mine]] of [[Las Medulas]] was one of the largest of their mines. At least seven long aqueducts worked it, and the water streams were used to erode the soft deposits, and then wash the tailings for the valuable gold content.<ref>{{cite web|url=https://whc.unesco.org/en/list/803|title=Las Médulas|last=Centre|first=UNESCO World Heritage|website=Whc.unesco.org|language=en|access-date=2017-06-13}}</ref><ref>{{Cite news|url=http://www.patrimoniocastillayleon.com/en/las-medulas|title=Las Médulas|date=2014-10-30|work=Castilla y León World Heritage UNESCO|access-date=2017-06-13|language=es-ES}}</ref>

=== Arabic-Islamic world ===

In the [[Muslim world]] during the [[Islamic Golden Age]] and [[Arab Agricultural Revolution]] (8th–13th centuries), engineers made wide use of [[hydropower]] as well as early uses of [[tidal power]],<ref>[[Ahmad Y. al-Hassan]] (1976). ''Taqi al-Din and Arabic Mechanical Engineering'', pp. 34–35. Institute for the History of Arabic Science, [[University of Aleppo]].</ref> and large hydraulic [[factory]] complexes.<ref>[[Maya Shatzmiller]], p. 36.</ref> A variety of water-powered industrial mills were used in the Islamic world, including [[fulling]] mills, [[gristmill]]s, [[paper mill]]s, [[Rice huller|hullers]], [[sawmill]]s, [[ship mill]]s, [[stamp mill]]s, [[steel mill]]s, [[Sugar refinery|sugar mills]], and [[tide mill]]s. By the 11th century, every province throughout the Islamic world had these industrial mills in operation, from [[Al-Andalus]] and [[North Africa]] to the [[Middle East]] and [[Central Asia]].<ref name=Lucas>Adam Robert Lucas (2005), "Industrial Milling in the Ancient and Medieval Worlds: A Survey of the Evidence for an Industrial Revolution in Medieval Europe," ''Technology and Culture'' '''46''' (1), pp. 1–30 [10].</ref> Muslim engineers also used [[water turbine]]s, employed [[gear]]s in watermills and water-raising machines, and pioneered the use of [[dams]] as a source of water power, used to provide additional power to watermills and water-raising machines.<ref name=Hassan>[[Ahmad Y. al-Hassan]], [http://www.history-science-technology.com/Articles/articles%2071.htm Transfer Of Islamic Technology To The West, Part II: Transmission Of Islamic Engineering] {{webarchive|url=https://web.archive.org/web/20080218171021/http://www.history-science-technology.com/Articles/articles%2071.htm |date=18 February 2008 }}</ref>

[[Al-Jazari]] (1136–1206) described designs for 50 devices, many of them water-powered, in his book, ''The Book of Knowledge of Ingenious Mechanical Devices'', including water clocks, a device to serve wine, and five devices to lift water from rivers or pools. These include [[Scoop wheel|an endless belt with jugs attached]] and a reciprocating device with hinged valves.<ref>{{cite web|last1=Al-Hassani|first1=Salim|title=800 Years Later: In Memory of Al-Jazari, A Genius Mechanical Engineer|url=http://muslimheritage.com/article/800-years-later-memory-al-jazari-genius-mechanical-engineer|website=Muslim Heritage|date=30 January 2008 |publisher=The Foundation for Science, Technology, and Civilisation|access-date=30 April 2015}}</ref>

The earliest [[Program (machine)|programmable machines]] were water-powered devices developed in the Muslim world. A [[music sequencer]], a programmable [[musical instrument]], was the earliest type of programmable machine. The first music sequencer was an automated water-powered [[flute]] player invented by the [[Banu Musa]] brothers, described in their ''[[Book of Ingenious Devices]]'', in the 9th century.<ref name=Koetsier>{{Citation |last1=Koetsier |first1=Teun  |year=2001 |title=On the prehistory of programmable machines: musical automata, looms, calculators |journal=Mechanism and Machine Theory |volume=36 |issue=5 |pages=589–603 |publisher=Elsevier |doi=10.1016/S0094-114X(01)00005-2 |postscript=.}}</ref><ref>{{cite journal |last1=Kapur |first1=Ajay |last2=Carnegie |first2=Dale |last3=Murphy |first3=Jim |last4=Long |first4=Jason |title=Loudspeakers Optional: A history of non-loudspeaker-based electroacoustic music |journal=[[Organised Sound]] |date=2017 |volume=22 |issue=2 |pages=195–205 |doi=10.1017/S1355771817000103 |publisher=[[Cambridge University Press]] |issn=1355-7718|doi-access=free }}</ref> In 1206, Al-Jazari invented water-powered programmable automata/[[robot]]s. He described four [[automaton]] musicians, including drummers operated by a programmable [[drum machine]], where they could be made to play different rhythms and different drum patterns.<ref name=Sharkey>Professor Noel Sharkey, [https://web.archive.org/web/20070629182810/http://www.shef.ac.uk/marcoms/eview/articles58/robot.html A 13th Century Programmable Robot (Archive)], [[University of Sheffield]].</ref>

== Modern history ==

During the mid 16th century, Italian engineer [[Giuseppe Ceredi]] advanced the design of the [[Archimedes' screw|Archimedean screw]] pump, applying mathematical principles to improve its efficiency for irrigation and drainage and secured a patent for his developments. Ceredi's innovations, documented in ''Tre discorsi sopra il modo d'alzar acque da' luoghi bassi'' (1567), led to widespread adoption of the technology throughout Southern Europe.<ref>{{Cite book |last=Traetta |first=Luigi |title=Explorations in the History and Heritage of Machines and Mechanisms |date=2018-12-12 |chapter=Giuseppe Ceredi. A Hydraulic Engineer in 16th-Century Italy |series=History of Mechanism and Machine Science |volume=37 |pages=17–27 |doi=10.1007/978-3-030-03538-9_2 |isbn=978-3-030-03537-2 |s2cid=115285603 }}</ref><ref>{{Cite web |title=Giuseppe Ceredi - |url=https://zaalbooks.nl/books/book.php?full=&sort=&cat=Science%2520%2526%2520Technology&mod=hoofd&hfdid=&subid=&page=1&bnr=26487&length=8&cust_id=990048 |access-date=2025-03-24 |website=zaalbooks.nl}}</ref> In 1619 [[Benedetto Castelli]], a student of [[Galileo Galilei]], published the book ''Della Misura dell'Acque Correnti'' or "On the Measurement of Running Waters," one of the foundations of modern hydrodynamics. He served as a chief consultant to the Pope on hydraulic projects, i.e., management of rivers in the Papal States, beginning in 1626.<ref>{{cite web|url=http://galileo.rice.edu/sci/castelli.html|title=The Galileo Project – Science – Benedetto Castelli|website=Galileo.rice.edu}}</ref> The science and engineering of water in Italy from 1500-1800 in books and manuscripts is presented in an illustrated catalog published in 2022.<ref>Andrews, Mark E. 2022. ''The Science and Engineering of Water: An Illustrated Catalogue of Books and Manuscripts on Italian Hydraulics 1500-1800.'' Toronto: AE Publications.</ref>

[[Blaise Pascal]] (1623–1662) studied fluid hydrodynamics and hydrostatics, centered on the principles of hydraulic fluids. His discovery on the theory behind hydraulics led to his invention of the [[hydraulic press]], which multiplied a smaller force acting on a smaller area into the application of a larger force totaled over a larger area, transmitted through the same pressure (or exact change of pressure) at both locations. [[Pascal's law]] or principle states that for an incompressible fluid at rest, the difference in pressure is proportional to the difference in height, and this difference remains the same whether or not the overall pressure of the fluid is changed by applying an external force. This implies that by increasing the pressure at any point in a confined fluid, there is an equal increase at every other end in the container, i.e., any change in pressure applied at any point of the liquid is transmitted undiminished throughout the fluids.

A French physician, [[Jean Léonard Marie Poiseuille|Poiseuille]] (1797–1869) researched the flow of blood through the body and discovered an important law governing the rate of flow with the diameter of the tube in which flow occurred.<ref>Sutera and Skalak, Salvatore and Richard. The History of Poiseuille's Law. Annu. Rev. Fluid Mech. 1993. 25: 1-19.</ref>{{Citation needed|date=May 2010}}

Several cities developed citywide [[hydraulic power network]]s in the 19th century, to operate machinery such as lifts, cranes, capstans and the like. [[Joseph Bramah]]<ref>{{cite web|url=http://www.robinsonlibrary.com/technology/engineering/biography/bramah.htm |archive-url=https://web.archive.org/web/20061024053301/http://www.robinsonlibrary.com/technology/engineering/biography/bramah.htm |url-status=usurped |archive-date=24 October 2006 |title=Joseph Bramah |website=Robinsonlibrary.com |date=2014-03-23 |access-date=2014-04-08}}</ref> (1748–1814) was an early innovator and [[William Armstrong, 1st Baron Armstrong|William Armstrong]]<ref>{{cite web|url=http://www.victorianweb.org/technology/engineers/armstrong.html |title=William George Armstrong, Baron Armstrong of Cragside (1810-1900) |website=Victorianweb.org |date=2005-12-22 |access-date=2014-04-08}}</ref> (1810–1900) perfected the apparatus for power delivery on an industrial scale. In London, the [[London Hydraulic Power Company]]<ref>{{cite web|url=http://www.subbrit.org.uk/sb-sites/sites/h/hydraulic_power_in_london/index.shtml |title=Subterranea Britannica: Sites: Hydraulic power in London |website=Subbrit.org.uk |date=1981-09-25 |access-date=2014-04-08}}</ref> was a major supplier its pipes serving large parts of the [[West End of London]], [[City of London|City]] and the [[London Docks|Docks]], but there were schemes restricted to single enterprises such as docks and [[railway]] [[goods yard]]s.

== Hydraulic models ==

After students understand the basic principles of hydraulics, some teachers use a hydraulic [[analogy]] to help students learn other things.
For example:
* The [[MONIAC Computer]] uses water flowing through hydraulic components to help students learn about economics.
* The [[thermal resistance#Analogies|thermal-hydraulic analogy]] uses hydraulic principles to help students learn about thermal circuits.
* The electronic–[[hydraulic analogy]] uses hydraulic principles to help students learn about electronics.

The [[conservation of mass]] requirement combined with fluid [[compressibility]] yields a fundamental relationship between pressure, fluid flow, and volumetric expansion, as shown below:<ref>{{cite web |url=http://opac.vimaru.edu.vn/edata/DHHH/2017/02/22/SDHLT%2002954%20-%20Hydraulic%20control%20systems.pdf |title=Archived copy |access-date=23 April 2018 |archive-url=https://web.archive.org/web/20180423232738/http://opac.vimaru.edu.vn/edata/DHHH/2017/02/22/SDHLT%2002954%20-%20Hydraulic%20control%20systems.pdf |archive-date=23 April 2018 |url-status=dead }}</ref>

: <math>\frac{dp}{dt} = \frac{\beta}{V} \left(\sum_\text{in} Q - \frac{dV}{dt}\right)</math>

Assuming an incompressible fluid or a "very large" ratio of compressibility to contained fluid volume, a finite rate of pressure rise requires that any net flow into the collected fluid volume create a volumetric change.

== See also == 
* [[Affinity laws]]
* [[Bernoulli's principle]]
* [[Hydraulic brake]]
* [[Hydraulic cylinder]]
* [[Hydraulic engineering]]
* [[Hydrology]]
* [[International Association for Hydro-Environment Engineering and Research]]
* [[Miniature hydraulics]]

== Notes ==

{{refs}}

== References ==
* {{citation | author1=Rāshid, Rushdī | author2=Morelon, Régis | title=Encyclopedia of the history of Arabic science | year=1996 | publisher=Routledge | location=London | isbn=978-0-415-12410-2 |postscript=. |ref=none}}

== External links ==
{{commonscat}}
{{Wikibooks|School Science|Hydraulics demonstration}}

* [https://web.archive.org/web/20090726193354/http://www.grc.nasa.gov/WWW/K-12/WindTunnel/Activities/Pascals_principle.html Pascal's Principle and Hydraulics] (archived copy)
* [http://www.hydraulicmania.com The principle of hydraulics]
* [http://www.iahrmedialibrary.net IAHR media library Web resource of photos, animation & video]
* [http://ocw.mit.edu/courses/civil-and-environmental-engineering/1-060-engineering-mechanics-ii-spring-2006/lecture-notes/ MIT hydraulics course notes]

{{Hydraulics}}

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