Editing Arc measurement (section)

==History==
{{Main|Meridian arc#History}}

The first known arc measurement was performed by [[Eratosthenes' arc measurement|Eratosthenes]] (240 BC) between Alexandria and Syene in what is now Egypt, determining the radius of the Earth with remarkable correctness. 
In the early 8th century, [[Yi Xing]] performed a similar survey.<ref name="Hsu 1993 pp. 90–100">{{cite journal | last=Hsu | first=Mei-Ling | title=The Qin maps: A clue to later Chinese cartographic development | journal=Imago Mundi | publisher=Informa UK Limited | volume=45 | issue=1 | year=1993 | issn=0308-5694 | doi=10.1080/03085699308592766 | pages=90–100}}</ref>

The French physician [[Jean Fernel]] measured the arc in 1528. The Dutch geodesist [[Willebrord Snellius|Snellius]] (~1620) repeated the experiment between [[Alkmaar]] and [[Bergen op Zoom]] using more modern geodetic instrumentation (''[[Snellius' triangulation]]'').

Later arc measurements aimed at determining the [[flattening]] of the Earth ellipsoid by measuring at different [[geographic latitude]]s. The first of these was the ''[[French Geodesic Mission]]'', commissioned by the [[French Academy of Sciences]] in 1735–1738, involving measurement expeditions to Lapland ([[Pierre Louis Maupertuis|Maupertuis]] et al.) and Peru ([[Pierre Bouguer]] et al.).

[[Friedrich Georg Wilhelm von Struve|Struve]] measured a [[geodetic control network]] via [[triangulation (surveying)|triangulation]] between the [[Arctic Sea]] and the [[Black Sea]], the ''[[Struve Geodetic Arc]]''. 

[[File:'The Adventures of Three Englishmen and Three Russians in South Africa' by Jules Férat 15.jpg|thumb|Imaginary arc measurement described by [[Jules Verne]] in his book ''[[The Adventures of Three Englishmen and Three Russians in South Africa]]'' (1872).]]

=== Chronological list ===
This is a partial chronological list of arc measurements:<ref>{{cite book | title=A history of the determination of the figure of the earth from arc measurements |author= Butterfield, Arthur Dexter | publisher=Internet Archive | date=1906 | page=156 | url=https://archive.org/details/ahistorydetermi00buttgoog/page/n168/mode/1up | ref={{sfnref|Internet Archive|2016}} | access-date=2025-01-26}}</ref><ref>{{cite web | title=Arc Measures | website=International Institution for the History of Surveying and Measurement | url=https://www.fig.net/organisation/perm/hsm/history_of/measurements/arc.asp | ref={{sfnref|International Institution for the History of Surveying and Measurement}} | access-date=2025-01-27}}</ref>
* 230 B.C.: [[Eratosthenes' arc measurement]]
* 100 B.C.: [[Posidonius' arc measurement]]
* 724 AD: [[Yi Xing's arc measurement]]
* 827 A.D.: [[Al-Ma'mun's arc measurement]]
* 1528: [[Fernel's arc measurement]]
* 1617: [[Snellius' survey]]
* 1633-1635: [[Norwood's arc measurement]]
* 1658: [[Riccioli and Grimaldi's arc measurement]]
* 1669: [[Picard's arc measurement]]
* 1684-1718: [[Dunkirk-Collioure arc measurement (Cassini, Cassini, and de La Hire)]]
* 1736-1737: [[French Geodesic Mission to Lapland]] 
* 1735-1739: [[French Geodesic Mission to the Equator]]
* 1740: [[Dunkirk-Collioure arc measurement (Cassini de Thury and de Lacaille)]]
* 1750-1751: [[Maire and Boscovich's arc measurement]]
* 1752: [[De Lacaille's arc measurement]]
* 1791-1853: [[Principal Triangulation of Great Britain]]
* 1792-1798: [[meridian arc of Delambre and Méchain]]
* 1802–1841: the [[Great Trigonometric Survey of India]]
* 1806-1809: [[Arago and Biot's arc measurement]]
* 1816-1855: [[Struve Geodetic Arc]]
* 1821-1825: [[Gauss' geodetic survey]]
* 1841-1848: [[Maclear's arc measurement]]
* 1879: [[West Europe-Africa Meridian-arc]]
* 1899-1902: [[Swedish–Russian Arc-of-Meridian Expedition]]
* 1921: [[Hopfner's arc measurement]]