Editing Compass (section)

== History ==
{{Main|History of the compass}}
===Natural magnet===
One of the earliest known references to lodestone's magnetic properties was made by 6th century BC Greek philosopher [[Thales of Miletus]],<ref>{{cite web | last = Brand | first = Mike | author2 = Sharon Neaves | author3 = Emily Smith | title = Lodestone | work = Museum of Electricity and Magnetism, Mag Lab U | publisher = US National High Magnetic Field Laboratory | year = 1995 | url = http://www.magnet.fsu.edu/education/tutorials/museum/lodestone.html | access-date = 2009-06-21 | archive-url = https://web.archive.org/web/20090501063207/http://www.magnet.fsu.edu/education/tutorials/museum/lodestone.html | archive-date = 2009-05-01 | url-status = dead }}</ref> whom the ancient Greeks credited with discovering lodestone's attraction to iron and other lodestones.<ref>{{cite book | last = Keithley | first = Joseph F. | title = The Story of Electrical and Magnetic Measurements: From 500 B.C. to the 1940s | publisher = John Wiley and Sons | year = 1999 | pages = 2 | url = https://books.google.com/books?id=uwgNAtqSHuQC | isbn = 0-7803-1193-0}}</ref> The name ''[[magnet]]'' may come from lodestones found in [[Magnesia ad Sipylum|Magnesia]], [[Anatolia]].<ref>The [[Ancient Greek|Greek]] term μαγνῆτις λίθος ''magnētis lithos'' (see [https://archive.org/details/bub_gb_BkS2KW7u76MC ''Platonis Opera''], Meyer and Zeller, 1839, p. 989) means "Magnesian stone". It is uncertain whether the adjective μαγνῆτις "of Magnesia" should be taken to refer to the city ''Magnesia ad Sipylum'' in [[Lydia]] (modern-day [[Manisa, Turkey]]) or after the Greek region of [[Magnesia (regional unit)|Magnesia]] itself (whence came the colonist who founded the Lydian city); see, for example, {{cite web|url=http://www.languagehat.com/archives/001914.php |title=Magnet |work=Language Hat blog |date=28 May 2005 |access-date = 22 March 2013}} See also: Paul Hewitt, ''Conceptual Physics''. 10th ed. (2006), p. 458.</ref> The [[History of India|ancient Indian]] medical text ''[[Sushruta Samhita]]'' describes using magnetic properties of the lodestone to remove arrows embedded in a person's body.{{citation needed|date=July 2024}}

<!-- The following is partly identical to [[Magnetism#History]] -->
The earliest Chinese literary reference to magnetism occurs in the 4th-century BC ''Book of the Devil Valley Master'' (''[[Guiguzi]]'').<ref>The section "Fanying 2" ([[:s:鬼谷子|反應第二]]) of ''The [[Guiguzi]]'': "{{lang|zh|其察言也，不失若磁石之取鍼，舌之取燔骨}}".</ref>
In the chronicle ''[[Lüshi Chunqiu]]'', from the 2nd century BC, it is explicitly stated that "the lodestone makes [[iron]] come or it attracts it."<ref>{{Cite book |title=Encyclopedia of Chinese History |last= Dillon |first= Michael |publisher= Routledge |year=2017 |isbn=978-0415426992 |pages=98}}</ref><ref name=Li54>{{cite journal |last=Li |first=Shu-hua |title=Origine de la Boussole II. Aimant et Boussole |journal=Isis |volume=45 |number=2 |year=1954 |pages=175–196|jstor=227361|doi=10.1086/348315|s2cid=143585290 | quote = un passage dans le ''[[Lüshi Chunqiu|Liu-che-tch'ouen-ts'ieou]]'' [...]: “La pierre d'aimant fait venir le fer ou elle l'attire.” | language = fr}}<br /> From the section "''Jingtong''" ({{lang|zh|精通}}) of the "Almanac of the Last Autumn Month" ({{lang|zh|季秋紀}}): "{{lang|zh|慈石召鐵，或引之也}}]"</ref>

===Artificial compass===
[[File:Model Si Nan of Han Dynasty.jpg|thumb|Model of a lodestone compass from [[Han dynasty]]]]
Some claims state that the first compasses in ancient [[Han dynasty]] China were made of [[lodestone]], a naturally magnetized ore of iron.<ref name="cambridge1">{{cite book |last=Lowrie |first=William |url=https://archive.org/details/fundamentalsgeop00will |title=Fundamentals of Geophysics |publisher=Cambridge University Press |year=2007 |isbn=978-0-521-67596-3 |edition=2nd |location=London |pages=[https://archive.org/details/fundamentalsgeop00will/page/n290 281] |quote=Early in the Han dynasty, between 300 and 200 BC, the Chinese fashioned a rudimentary compass out of lodestone&nbsp;... This compass may have been used in the search for gems and in the selection of sites for houses&nbsp;... Their directive power led to the use of compasses for navigation... |url-access=limited}}</ref><ref name="guarnieri 7-1">{{Cite journal|last=Guarnieri|first=M.|year=2014|title=Once Upon a Time, the Compass|journal=IEEE Industrial Electronics Magazine|volume=8|issue=2|pages=60–63|doi=10.1109/MIE.2014.2316044|s2cid=11949042}}</ref> The earliest mention of a needle's attraction appears in a work composed between 20 and 100 AD, the ''[[Lunheng]]'' (''Balanced Inquiries''): "A lodestone attracts a needle."<ref>In the section "[https://archive.org/stream/lunheng02wang#page/350/mode/1up A Last Word on Dragons]" ({{lang|zh|亂龍篇}} ''Luanlong'') of the ''[[Lunheng]]'': "[[Amber]] takes up straws, and a load-stone attracts needles" ({{lang|zh|頓牟掇芥，磁石引針}}).</ref> In the 2nd century BC, Chinese [[Geomancy|geomancers]] were experimenting with the magnetic properties of lodestone to make a "south-pointing spoon" for divination. When it is placed on a smooth bronze plate, the spoon would invariably rotate to a north–south axis.<ref>{{Cite book |title=Echoes from Old China: Life, Legends, and Lore of the Middle Kingdom |last=Tom |first=K. S. |publisher=University of Hawaii Press |year=1989 |pages=108}}</ref><ref>{{Cite book |title=Chinese Fans: Artistry and Aesthetics  |last= Qian  |first= Gonglin |publisher=Long River Press |year=2000 |isbn= 978-1592650200 |pages=98}}</ref><ref>{{Cite book |title=The History of China: (The Greenwood Histories of the Modern Nations) |last=Curtis Wright  |first=David |publisher=Greenwood Publishing Group |year=2001 |pages=42}}</ref> While this has been shown to work, archaeologists have yet to discover an actual spoon made of magnetite in a Han tomb.<ref>Joseph Needham, ''Clerks and Craftsmen in China and the West: Lectures and Addresses on the History of Science and Technology''. Cambridge: University Press, 1970, p. 241.</ref> A similar compass that used an iron fish to point north in a vessel of oil appeared in [[South India|Southern India]] in the 4th century AD.<ref>{{cite book |title=Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures |publisher=Springer |year=2008 |isbn=978-1-4020-4559-2 |editor=Helaine Selin |page=197}}</ref><ref>{{cite book |url=https://books.google.com/books?id=HUAPAAAAIAAJ&q=%22matsya+yantra%22 |title=The American Journal of Science |year=1919 |accessdate=2009-06-30}}</ref> 

Later compasses were made of iron needles, magnetized by striking them with a lodestone, which appeared in China by 1088 during the [[Song dynasty]], [[Dream Pool Essays|as described]] by [[Shen Kuo]].<ref name=merrill>{{cite book|last=Merrill|first=Ronald T.|title=The Earth's magnetic field: Its history, origin and planetary perspective|year=1983|publisher=Academic press|location=San Francisco|isbn=978-0-12-491242-7|page=[https://archive.org/details/earthsmagneticfi00merr/page/1 1]|edition=2nd printing|author2=McElhinny, Michael W.|url=https://archive.org/details/earthsmagneticfi00merr/page/1}}</ref> Dry compasses began to appear around 1300 in [[Medieval Europe]] and the [[Islamic world]].<ref name="Lane, p. 615"/><ref name=OEPST /> This was supplanted in the early 20th century by the liquid-filled magnetic compass.<ref name="W. H. Creak 238-239">{{cite journal|author=Creak, W.H. |title=The History of the Liquid Compass|journal=The Geographical Journal|volume=56|issue=3 |year=1920|pages=238–239|doi=10.2307/1781554|jstor=1781554|bibcode=1920GeogJ..56..238C }}</ref>