Editing Metre Convention (section)

=== Swiss, American, Spanish and Egyptian cartography ===
[[File:HasslerCollection 001.jpg|thumb|Triangulation near [[New York City]], 1817|left]]

The [[Helvetic Republic]] adopted the [[metric system]] by law in 1801.<ref>{{Cite web |title=Système métrique |url=https://hls-dhs-dss.ch/fr/articles/013754/2014-05-22/ |access-date=2025-04-08 |website=hls-dhs-dss.ch |language=fr}}</ref> In 1805, a Swiss immigrant [[Ferdinand Rudolph Hassler]] brought copies of the French metre and kilogram to the United States. In 1830 the [[United States Congress|Congress]] decided to create uniform standards for length and weight in the United States.<ref name=":3">{{Cite web |title=e-expo: Ferdinand Rudolf Hassler |url=https://www.f-r-hassler.ch/en/weights/index.html |access-date=2025-04-07 |website=www.f-r-hassler.ch}}</ref> Hassler was mandated to work out the new standards and proposed to adopt the metric system. The United States Congress opted for the [[Yard#Physical standards|British Parliamentary Standard Yard of 1758]] and the British [[Imperial units#Mass and weight|Troy Pound of 1824]] as length and weight standards.<ref name=":3" /> Nevertheless Ferdinand Rudolph Hassler's use of the metre and the creation of the [[National Institute of Standards and Technology|Office of Standard Weights and Measures]] as an office within the [[United States Coast and Geodetic Survey|Coast Survey]] contributed to the introduction of the [[Metric Act of 1866]] allowing the use of the metre in the United States.<ref name="Metric Act of 1866">{{Cite web |title=Metric Act of 1866 – US Metric Association |url=https://usma.org/laws-and-bills/metric-act-of-1866#locale-notification |access-date=2021-03-15 |website=usma.org}}</ref>

In 1816, Ferdinand Rudolph Hassler was appointed first Superintendent of the [[United States Coast and Geodetic Survey|Survey of the Coast]].<ref>{{cite web |url=https://celebrating200years.noaa.gov/historymakers/hassler/welcome.html |title=NOAA 200th Top Tens: History Makers: Ferdinand Rudolph Hassler |publisher=National Oceanic and Atmospheric Administration |location=US |date=2024-03-19 |access-date=2024-10-17}}</ref><ref name="Cajori-1921">{{Cite journal |last=Cajori |first=Florian |date=1921 |title=Swiss Geodesy and the United States Coast Survey |url=https://www.jstor.org/stable/6721 |journal=The Scientific Monthly |volume=13 |issue=2 |pages=117–129 |bibcode=1921SciMo..13..117C |issn=0096-3771}}</ref> Trained in geodesy in Switzerland, France and [[Germany]], Hassler had brought a standard metre made in Paris to the United States in October 1805. He designed a baseline apparatus which instead of bringing different bars in actual contact during measurements,<ref name="Cajori-1921" /> used only one bar calibrated on the Committee meter, an authenthic copy of the {{Lang|fr|Mètre des Archives}},<ref>{{Cite book |url=https://play.google.com/store/books/details?id=NiEEAQAAIAAJ |title=National Bureau of Standards Miscellaneous Publication |date=1966 |publisher=U.S. Government Printing Office |pages=529 |language=en}}</ref><ref name=":10">{{Cite journal |last=Clarke |first=Alexander Ross |last2=James |first2=Henry |date=1873 |title=XIII. Results of the comparisons of the standards of length of England, Austria, Spain, United States, Cape of Good Hope, and of a second Russian standard, made at the Ordnance Survey Office, Southampton. With a preface and notes on the Greek and Egyptian measures of length by Sir Henry James |url=https://royalsocietypublishing.org/doi/10.1098/rstl.1873.0014 |journal=Philosophical Transactions of the Royal Society of London |volume=163 |pages=445–469 |doi=10.1098/rstl.1873.0014}}</ref> and optical contact.<ref name="Cajori-1921" /><ref>{{Cite book |last1=American Philosophical Society. |url=https://www.biodiversitylibrary.org/item/26092 |title=Transactions of the American Philosophical Society |last2=Society |first2=American Philosophical |last3=Poupard |first3=James |date=1825 |volume=new ser.:v.2 (1825) |location=Philadelphia [etc.] |pages=234–278}}</ref> In 1830, Hassler became head of the Office of Weights and Measures, which became a part of the Survey of the Coast. He compared various units of length used in the [[United States]] at that time and measured [[Thermal expansion|coefficients of expansion]] to assess temperature effects on the measurements.<ref name="Parr-2006">{{Cite journal |last=Parr |first=Albert C. |date=2006-04-01 |title=A Tale About the First Weights and Measures Intercomparison in the United States in 1832 |url=https://www.nist.gov/publications/tale-about-first-weights-and-measures-intercomparison-united-states-1832 |journal=Journal of Research of the National Institute of Standards and Technology |language=en |volume=111 |issue=1 |pages=31–32, 36 |doi=10.6028/jres.111.003 |pmc=4654608 |pmid=27274915 |via=NIST}}</ref> In 1834, Hassler, measured at [[Fire Island]] the first [[Baseline (surveying)|baseline]] of the Survey of the Coast,<ref name=":5">{{Cite book |last1=Hassler |first1=Harriet |url=http://archive.org/details/ferdinandrudolph1068hass |title=Ferdinand Rudolph Hassler (1770–1843) |last2=Burroughs |first2=Charles A. |date=2007 |others=NIST Research Library |pages=51–52}}</ref> shortly before [[Louis Puissant]] declared to the French Academy of Sciences in 1836 that Jean Baptiste Joseph Delambre and Pierre Méchain had made errors in the [[Arc measurement|meridian arc measurement]], which had been used to determine the length of the metre.<ref name="Lebon-1899">{{Cite book |last=Lebon |first=Ernest |url=https://gallica.bnf.fr/ark:/12148/bpt6k949666 |title=Histoire abrégée de l'astronomie / par Ernest Lebon,... |date=1899 |pages=168–171 |language=EN}}</ref><ref>{{Cite book |last=Puissant |first=Louis |url=https://gallica.bnf.fr/ark:/12148/bpt6k5323385b |title=Nouvelle détermination de la distance méridienne de Montjouy à Formentera, dévoilant l'inexactitude de celle dont il est fait mention dans la base du système métrique décimal, par M. Puissant,... lu à l'Académie des sciences, le 2 mai 1836 |language=EN}}</ref>[[File:Appareil_Ibáñez.jpg|thumb|313x313px|Ibáñez apparatus calibrated on the metric Spanish standard and used at [[Aarberg]], in [[canton of Bern]], [[Switzerland]] in 1880.<ref>{{Cite book |last1=Hirsch |first1=A. |title=Le Réseau de Triangulation suisse |last2=Dumur |first2=J. |publisher=Commission géodésique suisse |year=1888 |volume=Troisième volume. La Mensuration des Bases |pages=3–4 |language=fr}}</ref>]]
In 1855, the Dufour map (French: ''Carte Dufour''), the first [[Topographic Map of Switzerland|topographic map of Switzerland]] for which the metre was adopted as the unit of length, won the gold medal at the Exposition Universelle.<ref>{{Cite news |last=Abplanalp |first=Andrej |date=2019-07-14 |title=Henri Dufour et la carte de la Suisse |url=https://blog.nationalmuseum.ch/fr/2019/07/dufour-le-cartographe/ |archive-url=https://web.archive.org/web/20241225163218/https://blog.nationalmuseum.ch/fr/2019/07/dufour-le-cartographe/ |archive-date=25 December 2024 |access-date=2025-01-25 |work=Musée national - Blog sur l'histoire suisse |language=de-DE |url-status=live }}</ref><ref>{{Cite journal |last=Dufour |first=G.-H. |date=1861 |title=Notice sur la carte de la Suisse dressée par l'État Major Fédéral |url=https://www.persee.fr/doc/globe_0398-3412_1861_num_2_1_7582 |journal=Le Globe. Revue genevoise de géographie |volume=2 |issue=1 |pages=5–22 |doi=10.3406/globe.1861.7582}}</ref> However, the baselines for this map were measured in 1834 with three toises long measuring rods calibrated on a toise made in 1821 by [[Jean Nicolas Fortin]] for [[Friedrich Georg Wilhelm von Struve]].<ref>{{Cite journal |last=Seligmann |first=A. E. M. |date=1923 |title=La Toise de Belgique |journal=Ciel et Terre, Bulletin of the Société Belge d'Astronomie |volume=39 |page=25}}</ref><ref name="Clarke-1867">{{Cite journal |last1=Clarke |first1=Alexander Ross |last2=James |first2=Henry |date=1867-01-01 |title=X. Abstract of the results of the comparisons of the standards of length of England, France, Belgium, Prussia, Russia, India, Australia, made at the ordnance Survey Office, Southampton |url=https://royalsocietypublishing.org/doi/10.1098/rstl.1867.0010 |journal=Philosophical Transactions of the Royal Society of London |volume=157 |page=174 |doi=10.1098/rstl.1867.0010 |s2cid=109333769}}</ref> The Spanish standard, a geodetic measuring device calibrated on the metre devised by [[Carlos Ibáñez e Ibáñez de Ibero]] and [[Frutos Saavedra Meneses]], was also displayed by [[Jean Brunner]] at the Exhibition.<ref>{{Cite periodical |last=Brenni |first=Paolo |date=1996 |title=19th Century French Scientific Instrument Makers XI: The Brunners and Paul Gauher |url=https://www.unav.es/gep/TheBrunnersCartaParis.pdf |archive-url=https://web.archive.org/web/20241203014633/https://www.unav.es/gep/TheBrunnersCartaParis.pdf |archive-date=3 December 2024 |access-date=2025-01-25 |periodical=Bulletin of the Scientific Instrument Society |number=49 |url-status=live }}</ref><ref>{{Cite journal |last=Brenni |first=Paolo |date=1996 |title=19th Century French Scientific Intrument Makers |url=https://www.unav.es/gep/TheBrunnersCartaParis.pdf |journal=Bulletin of the Scientific Instrument Society |issue=49 |page=4 |archive-url=https://web.archive.org/web/20241203014633/https://www.unav.es/gep/TheBrunnersCartaParis.pdf |archive-date=3 December 2024}}</ref> Carlos Ibáñez e Ibáñez de Ibero recognized that the end standards with which the most perfect devices of the eighteenth century and those of the first half of the nineteenth century were still equipped, that [[Jean-Charles de Borda]] or [[Friedrich Bessel|Friedrich Wilhelm Bessel]] simply joined measuring the intervals by means of screw tabs or glass wedges, would be replaced advantageously for accuracy by microscopic measurements, a system designed in [[Switzerland]] by Ferdinand Rudolph Hassler and [[Johann Georg Tralles]],<ref>{{Cite web |last=Wolf |first=Rudolf |date=1891-01-01 |title=Histoire de l'appareil Ibañez-Brunner in Comptes rendus hebdomadaires des séances de l'Académie des sciences / publiés... par MM. les secrétaires perpétuels |url=https://gallica.bnf.fr/ark:/12148/bpt6k3068q |access-date=2023-08-31 |website=Gallica |pages=370–371 |language=FR}}</ref> and which Ibáñez ameliorated using a single standard with lines marked on the bar. Regarding the two methods by which the effect of temperature was taken into account, Ibáñez used both the bimetallic rulers, in platinum and brass, which he first employed for the central base of Spain,<ref name="Brunner-18572">{{Cite web |last=Brunner |first=Jean |date=1857-01-01 |title=Appareil construit pour les opérations au moyen desquelles on prolongera dans toute l'étendue de l'Espagne le réseau trigonométrique qui couvre la France in Comptes rendus hebdomadaires des séances de l'Académie des sciences / publiés... par MM. les secrétaires perpétuels |url=https://gallica.bnf.fr/ark:/12148/bpt6k3001w |access-date=2023-08-31 |website=Gallica |pages=150–153 |language=FR}}</ref> and the simple iron ruler with inlaid mercury thermometers which was used in Switzerland.<ref name=":6" /><ref name=":11">{{Cite EB1911 |wstitle= Geodesy |volume = 11 |last1= Clarke |first1= Alexander Ross |author-link1= Alexander Ross Clarke |last2= Helmert |first2= Friedrich Robert |author-link2= Friedrich Robert Helmert |pages= 607-615 |short=1}}</ref> On the sidelines of the [[Exposition Universelle (1855)]] and the second [[International Statistical Institute|Congress of Statistics]] held in Paris, an association with a view to obtaining a uniform decimal system of measures, weights and currencies was created in 1855.<ref name=":4" /> Under the impetus of this association, a Committee for Weights and Measures and Monies (French: ''Comité des poids, mesures et monnaies'') would be created during the [[Exposition Universelle (1867)]] in Paris and would call for the international adoption of the metric system.<ref name=":8">{{Cite web |title=History – The BIPM 150 |url=https://thebipm150.org/history/ |access-date=2025-04-08 |language=fr-FR}}</ref><ref name=":4" />

[[Egyptian astronomy]] has ancient roots which were revived in the 19th century by the modernist impetus of [[Muhammad Ali of Egypt|Muhammad Ali]] who founded in Sabtieh, [[Boulaq]] district, in [[Cairo]] an Observatory which he was keen to keep in harmony with the progress of this science still in progress.<ref name="Ismāʿīl-Afandī Muṣṭafá-1864" /><ref name="Jamʻīyah al-Jughrāfīyah al-Miṣrīyah-1876" /> In 1858, a Technical Commission was set up to continue [[cadastral surveying]] inaugurated under Muhammad Ali. This Commission suggested to Viceroy [[Sa'id of Egypt|Mohammed Sa'id Pasha]] to buy geodetic devices which were ordered in France. While [[Mahmud Ahmad Hamdi al-Falaki]] was in charge, in Egypt, of the direction of the work of the general map, the viceroy entrusted to [[Ismail Mustafa al-Falaki]] the study, in Europe, of the precision apparatus calibrated against the metre intended to measure the geodesic bases and already built by [[Jean Brunner]] in Paris. Ismail Mustafa had the task to carry out the experiments necessary for determining the expansion coefficients of the two platinum and brass bars, and to compare the Egyptian standard with a known standard. The Spanish standard designed by Carlos Ibáñez e Ibáñez de Ibero and Frutos Saavedra Meneses was chosen for this purpose, as it had served as a model for the construction of the Egyptian standard.<ref name="Jamʻīyah al-Jughrāfīyah al-Miṣrīyah-1876" /><ref name="Ismāʿīl-Afandī Muṣṭafá-1864" /> In addition, the Spanish standard had been compared with [[Jean-Charles de Borda|Borda]]'s double-toise N°&nbsp;1, which served as a comparison module for the measurement of all geodesic bases in France,<ref name="Soler-1997">{{Cite journal |last=Soler |first=T. |date=1997-02-01 |title=A profile of General Carlos Ibáñez e Ibáñez de Ibero: first president of the International Geodetic Association |journal=Journal of Geodesy |language=en |volume=71 |issue=3 |pages=176–188 |bibcode=1997JGeod..71..176S |citeseerx=10.1.1.492.3967 |doi=10.1007/s001900050086 |issn=1432-1394 |s2cid=119447198}}</ref><ref name="Brunner">{{Cite web |last=Brunner |first=Jean |date=1857 |title=Comptes rendus hebdomadaires des séances de l'Académie des sciences / publiés... par MM. les secrétaires perpétuels |url=https://gallica.bnf.fr/ark:/12148/bpt6k3001w |access-date=2019-05-15 |website=Gallica |pages=150–153 |language=FR}}</ref> and was also to be compared to the Ibáñez apparatus.<ref name=":10" /><ref name="Soler-1997" /> In 1954, the connection of the southerly extension of the [[Struve Geodetic Arc]] with an arc running northwards from [[South Africa]] through [[Egypt]] would bring the course of a major [[meridian arc]] back to land where [[Eratosthenes]] had founded [[geodesy]].<ref>{{Cite news |title=Nomination of the STRUVE GEODETIC ARC for inscription on the WORLD HERITAGE LIST |url=https://whc.unesco.org/uploads/nominations/1187.pdf |pages=40, 143–144}}</ref>