Editing Hydrometer (section)

==History==
[[File : Hydrometer6455.png|thumb|upright=0.6|Hydrometer from ''Practical Physics'']]

The hydrometer probably dates  back to the Greek philosopher [[Archimedes]] (3rd century BC) who used its principles to find the density of various liquids.<ref>{{Cite book |last=Hornsey |first=Ian S. |title=A history of beer and brewing |date=2003 |publisher=Royal Society of Chemistry |isbn=978-0-85404-630-0 |series= |location=Cambridge |page=429 |language=en}}</ref><ref>{{Cite book |last=Bendick |first=Jeanne |title=Archimedes And The Door Of Science |publisher=Literary Licensing, LLC |year=2011 |isbn=9781258014889 |pages=63–64 |language=en |orig-date=1962}}</ref> An early description of a hydrometer comes from a Latin poem, written in the 2nd century AD by Remnius, who compared the use of a hydrometer to the method of [[Displacement (fluid)|fluid displacement]] used by Archimedes to determine the gold content of [[Hiero II of Syracuse|Hiero II's]] crown.<ref name="bensaude-vincent">{{cite book |last=Bensaude-Vincent |first=Bernadette |title=Instruments and Experimentation in the History of Chemistry |date=2000 |publisher=Massachusetts Institute of Technology Press |isbn=9780262082822 |editor1-last=Holmes |editor1-first=Frederic L. |editor-link=Frederic L. Holmes |page=153 |author-link=Bernadette Bensaude-Vincent |editor2-last=Levere |editor2-first=Trevor H. |editor-link2=Trevor H. Levere}}</ref>

[[Hypatia of Alexandria]] {{nowrap|(b. {{em|{{circa}}}} 350–}}370; d.{{nbs}}415 CE), an important female Greek mathematician, is the first person traditionally associated with the hydrometer.<ref name="bensaude-vincent"/> In a letter, [[Synesius|Synesius of Cyrene]] asks Hypatia, his teacher, to make a hydrometer for him:

<blockquote>
The instrument in question is a cylindrical tube, which has the shape of a flute and is about the same size. It has notches in a perpendicular line, by means of which we are able to test the weight of the waters. A cone forms a lid at one of the extremities, closely fitted to the tube. The cone and the tube have one base only. This is called the baryllium. Whenever you place the tube in water, it remains erect. You can then count the notches at your ease, and in this way ascertain the weight of the water.<ref>{{cite book |last=FitzGerald |first=Augustine |url= |title=The Letters of Synesius of Cyrene |date=1926 |publisher=Oxford University Press |page=99 |chapter=Letter 15 - To the Philosopher (Hypatia) |hdl=2027/mdp.39015008616180?urlappend=%3Bseq=105 |chapter-url=https://hdl.handle.net/2027/mdp.39015008616180?urlappend=%3Bseq=105%3Bownerid=13510798888320432-109}}</ref>
</blockquote>

According to the ''Encyclopedia of the History of Arabic Science'', it was used by [[Abū Rayhān al-Bīrūnī]] in the 11th century and described by [[Al-Khazini]] in the 12th century.<ref>{{cite book |last1=Rozhanskaya |first1=Mariam |title=[[Encyclopedia of the History of Arabic Science|Encyclopedia of the History of Arabic Science, Volume 2]] |last2=Levinova |first2=I. S. |publisher=[[Routledge]] |year=1996 |isbn=978-0-415-12411-9 |editor1=Rushdī Rāshid |pages=614–642 [ [https://books.google.com/books?id=Dy897SeErOQC&pg=PA639 639] ] |chapter=Statics |access-date=2019-03-26 |editor2=Régis Morelon |chapter-url=https://books.google.com/books?id=Dy897SeErOQC&pg=PA614 |name-list-style=}}</ref> It was rediscovered in 1612 by Galileo and his circle of friends, and used in experiments especially at the Accademia del Cimento.<ref>{{cite web |title=In-depth Hydrometer |url=https://catalogue.museogalileo.it/indepth/Hydrometer.html |access-date=2024-01-01 |website=Museo Galileo}}</ref> It appeared again in the 1675 work of Robert Boyle (who coined the name ''"hydrometer"''),<ref name="bensaude-vincent"/> with types devised by [[Antoine Baumé]] (the [[Baumé scale]]), [[William Nicholson (chemist)|William Nicholson]], and [[Jacques Charles|Jacques Alexandre César Charles]] in the late 18th century,<ref>{{cite journal |author=Blondel |first=Claude-Joseph |year=2003 |title=Un enfant illustre de Beaugency : le physicien et aéronaute Jacques Charles (1746-1823) |trans-title=An illustrious child of Beaugency: the physicist and aeronaut |url=https://gallica.bnf.fr/ark:/12148/bpt6k65454933 |journal=Les Publications de l'Académie d'Orléans, Agriculture, Sciences, Belles-lettres et Arts |language=fr |publisher=Académie d'Orléans |page=37 |number=4}}</ref> more or less contemporarily with [[Benjamin Sikes]]' discovery of the device by which the alcoholic content of a liquid can be automatically determined. The use of the Sikes device was made obligatory by British law in 1818.<ref>{{cite book |last=Denison |first=Merrill |date=1955 |title=The Barley and the Stream: The Molson Story |location=Toronto |publisher=McClelland & Stewart |page=132}}</ref>