History of the metre: Difference between revisions

With the [[French Revolution]] (1789) came a desire to replace many features of the [[Ancien Régime]], including [[Units of measurement in France before the French Revolution|the traditional units of measure]]. As a base unit of length, many scientists had favoured the [[seconds pendulum]] (a pendulum with a half-period of one second) one century earlier, but this was rejected as it had been discovered that this length varied from place to place with local gravity. A new unit of length, the ''metre'' was introduced – defined as one ten-millionth of the shortest distance from the North Pole to the equator [[Paris meridian|passing through Paris]], assuming an Earth [[flattening]] of {{Sfrac|1/|334}}.

The historical French official standard of the metre was made available in the form of the {{lang|fr|[[Mètre des Archives]]}}, a platinum bar held in Paris. During the mid nineteenth century, following the [[American Revolution]] and [[Decolonization of the Americas|independanceindependence of Latin America]], the metre gained adoption in [[Americas]], particularly in scientific usage, and it was officially established as an international measurement unit by the [[Metre Convention]] of 1875 at the beginning of the [[Second Industrial Revolution]].

The {{lang|fr|[[Mètre des Archives]]}} and its copies such as the Committee Meter were replaced from 1889 at the initiative of the [[International Association of Geodesy|International Geodetic Association]] by thirty [[platinum-iridium]] bars kept across the globe.<ref>{{Cite web|url=https://www.bipm.org/fr/measurement-units/history-si/international-metre-commission.html|title=BIPM - Commission internationale du mètre|website=www.bipm.org|access-date=13 November 2019}}</ref> A better [[standardization]] of the new prototypes of the metre and their comparisioncomparison with each other and with the historical standard involved the development of specialized measuring equipment and the definition of a reproducible temperature scale.<ref name="la définition du mètre">{{Cite web |title=BIPM – la définition du mètre |url=https://www.bipm.org/fr/measurement-units/history-si/evolution_metre.html |access-date=17 June 2019 |website=www.bipm.org |archive-date=30 April 2017 |archive-url=https://web.archive.org/web/20170430075245/http://www.bipm.org/fr/measurement-units/history-si/evolution_metre.html |url-status=dead }}</ref>

[[Kepler's laws of planetary motion]] served both to the discovery of [[Newton's law of universal gravitation]] and to the determination of the distance from Earth to the Sun by [[Giovanni Domenico Cassini]].<ref>{{Cite book |last=Bond, Peter, (1948- ...). |title=L'exploration du système solaire |date=2014 |publisher=De Boeck |others=Dupont-Bloch, Nicolas. |isbn=9782804184964 |edition=[Édition française revue et corrigée] |location=Louvain-la-Neuve |pages=5–6 |oclc=894499177}}</ref> They both also used a determination of the size of the Earth, then considered as a sphere, by [[Jean Picard]] through [[Triangulation (surveying)|triangulation]] of [[Paris meridian]]. In 1671, Jean Picard also measured the length of a [[seconds pendulum]] at [[Paris Observatory]] and proposed this unit of measurement to be called the astronomical radius (French: ''Rayon Astronomique''). He found the value of 440.5 [[ligne]]s of the Toise of Châtelet (a {{lang|fr|[[toise]]}} [English: [[fathom]]] is defined as 6 {{lang|fr|[[Pied (unit)|pieds]]}} <nowiki>[</nowiki>{{bracket|[[Foot (unit)|foot]]]}} or 72 {{lang|fr|[[Units of measurement in France before the French Revolution|pouces]]}} <nowiki>[</nowiki>{{bracket|[[inch]]es]}} or 864 {{lang|fr|[[ligne]]s}} <nowiki>[</nowiki>{{bracket|[[Line (unit)|lines]]]}}<ref>{{Cite book |last=Dubost |first=Christopher |url=https://books.google.com/books?id=4DMwfzakB40C&pg=PA403 |title=The Elements of Commerce; or, a treatise on different calculations,-operations of exchange, etc |date=1818 |pages=403 |language=en}}</ref>), which had been recently renewed. He proposed a universal toise (French: {{lang|fr|toise universelle}}) which was twice the length of the seconds pendulum.{{sfn|Bigourdan|1901|pages=8, 158–159}} In 1675, [[Tito Livio Burattini]] suggested the term ''{{Lang|it|metro cattolico}}'' meaning universal measure for this unit of length, but then it was discovered that the length of a seconds pendulum varies from place to place: French astronomer [[Jean Richer]] had measured the 0.3% difference in length between [[Cayenne]] (in French Guiana) and Paris.<ref name="Bigourdan">{{Cite book |last=Bigourdan |first=Guillaume |url=https://archive.org/details/lesystmemtri00bigo |title=Le système métrique des poids et mesures ; son établissement et sa propagation graduelle, avec l'histoire des opérations qui ont servi à déterminer le mètre et le kilogramme |date=1901 |publisher=Paris : Gauthier-Villars |others=University of Ottawa |pages=[https://archive.org/details/lesystmemtri00bigo/page/7 7], 148, 154}}</ref><ref name=":8" /><ref>{{Cite book |last=Simaan, Arkan. |title=La science au péril de sa vie : les aventuriers de la mesure du monde |date=2001 |publisher=Vuibert |isbn=2711753476 |location=Paris |pages=124–125 |oclc=300706536}}</ref><ref>{{Cite book |last=Picard |first=Jean |url=https://gallica.bnf.fr/ark:/12148/btv1b7300361b/f13.image |title=Mesure de la terre |date=1671 |pages=3–4 |language=fr |author-link=Jean Picard |via=[[Gallica]]}}</ref><ref>{{Cite book |last1=Bond |first1=Peter |title=L'exploration du système solaire |last2=Dupont-Bloch |first2=Nicolas |date=2014 |publisher=De Boeck |isbn=9782804184964 |location=Louvain-la-Neuve |pages=5–6 |language=fr |oclc=894499177}}</ref><ref>{{cite book |last1=Poynting |first1=John Henry |url=https://archive.org/details/bub_gb_TL4KAAAAIAAJ |title=A Textbook of Physics: Properties of Matter |last2=Thompson |first2=Joseph John |publisher=Charles Griffin |year=1907 |edition=4th |location=London |page=[https://archive.org/details/bub_gb_TL4KAAAAIAAJ/page/n30 20]}}</ref><ref>{{cite web |date=25 March 2021 |title=Science. 1791, l'adoption révolutionnaire du mètre |url=https://www.humanite.fr/science-1791-ladoption-revolutionnaire-du-metre-702009 |access-date=3 August 2021 |website=humanite.fr |language=fr}}</ref><ref>{{cite book |last1=Lucendo |first1=Jorge |url=https://books.google.com/books?id=4l3eDwAAQBAJ&pg=PT246 |title=Centuries of Inventions: Encyclopedia and History of Inventions |date=23 April 2020 |publisher=Jorge Lucendo |page=246 |language=en |access-date=2 August 2021}}</ref><ref>{{citation | title=Misura Universale | year=1675}}</ref>

[[Christiaan Huygens]] found out the [[centrifugal force]] which explained variations of gravitational acceleration depending on latitude. He also discovered that the [[seconds pendulum]] length was a means to measure gravitational acceleration. In the 18th century, in addition ofto its significance for [[cartography]], [[geodesy]] grew in importance as a means of empirically demonstrating the [[Gravity|theory of gravity]], which [[Émilie du Châtelet]] promoted in France in combination with [[Gottfried Wilhelm Leibniz|Leibniz's]] mathematical work and because the [[Earth radius|radius of the Earth]] was the unit to which all celestial distances were to be referred. Indeed, Earth proved to be an [[Spheroid|oblate spheroid]] through geodetic surveys in [[French Geodesic Mission to the Equator|Ecuador]] and [[French Geodesic Mission to Lapland|Lapland]] and this new data called into question the value of [[Earth radius]] as Picard had calculated it.<ref name="Perrier-19352">{{Cite journal |last=Perrier |first=Général |date=1935 |title=Historique Sommaire De La Geodesie |url=https://www.jstor.org/stable/43861533 |journal=Thalès |volume=2 |pages=117–129, p. 128 |issn=0398-7817 |jstor=43861533}}</ref><ref>{{Cite book |last=Badinter |first=Élisabeth |url=https://www.worldcat.org/oclc/1061216207 |title=Les passions intellectuelles |date=2018 |publisher=Robert Laffont |others=Normandie roto impr.) |isbn=978-2-221-20345-3 |location=Paris |oclc=1061216207}}</ref><ref>{{Cite journal |last=Touzery |first=Mireille |date=2008-07-03 |title=Émilie Du Châtelet, un passeur scientifique au XVIIIe siècle |url=https://journals.openedition.org/histoire-cnrs/7752 |journal=La revue pour l'histoire du CNRS |language=fr |issue=21 |doi=10.4000/histoire-cnrs.7752 |issn=1298-9800|doi-access=free }}</ref><ref name="Earth-19112">{{Cite EB1911|wstitle=Earth, Figure of the|volume=8|pages=801-813|short=1}}</ref><ref group="Note">:<math>T=2\pi\sqrt{\frac \ell g}. </math>

Being <math>T_{1/2}=1\ \mathrm{s}</math>, therefore <math>g={\ell\cdot \pi^2}</math>.</ref><ref group="Note">At the time the second was defined as a fraction of the Earth's rotation time and determined by clocks whose precision was checked by astronomical observations. In 1936 French and German astronomers found that Earth rotation's speed is irregular. Since 1967 atomic clocks define the second. For further information see [[atomic time]].</ref>[[File:Repsold.jpg|thumb|[[Gravimeter]] with variant of [[Repsold-Bessel pendulum]].]]According to [[Alexis Clairaut]], the study of variations in gravitational acceleration was a way to determine the [[figure of the Earth]], whose crucial parameter was the [[flattening]] of the [[Earth ellipsoid]]. In his famous work {{lang|fr|Théorie de la figure de la terre, tirée des principes de l'hydrostatique}} ('Theory of the Figure of the Earth, drawn from the Principles of Hydrostatics') published in 1743, [[Alexis Clairaut|Alexis Claude Clairaut]] synthesized the relationships existing between gravity and the shape of the Earth. Clairaut exposed there his [[Clairaut's theorem|theorem]] which established a relationship between [[gravity]] measured at different latitudes and the flattening of the Earth considered as a [[spheroid]] composed of concentric layers of variable densities. Towards the end of the 18th century, the geodesists sought to reconcile the values of flattening drawn from the measurements of meridian arcs with that given by Clairaut's spheroid drawn from the measurement of gravity. In 1789, [[Pierre-Simon de Laplace]] obtained by a calculation taking into account the measures of meridian arcs known at the time a flattening of {{Sfrac|1/|279}}. [[Gravimetry]] gave him a flattening of {{Sfrac|1/|359}}. [[Adrien-Marie Legendre]] meanwhile found at the same time a flattening of {{Sfrac|1/|305}}. The Weights and Measures Commission would adopt in 1799 a flattening of {{Sfrac|1/|334}} by combining the [[French Geodesic Mission to the Equator|arc of Peru]] and the data of the meridian arc of Delambre and Méchain. This value was the result of a conjecture based on too limited data. Thus the results of the [[French Geodesic Mission to Lapland|French Geodetic Mission to Lapland]] had been excluded, whereas a value close to {{Sfrac|1/|300}} would have been found, if they had been combined with those of the [[French Geodesic Mission to the Equator|French Geodetic Mission to the Equator]].<ref>{{Cite book |last=Quinn |first=Terry J. |title=From artefacts to atoms: the BIPM and the search for ultimate measurement standards |date=2012 |publisher=Oxford University Press |isbn=978-0-19-530786-3 |location=New York Oxford |pages=13}}</ref> In 1841, [[Friedrich Bessel|Friedrich Wilhelm Bessel]] would calculate the Earth's flattening from ten meridian arcs measured with sufficient accuracy using the method of [[least squares]] and found a value of {{Sfrac|1/|299.15}}. His [[Earth ellipsoid|reference ellipsoid]] would long be used by geodesists. An even more accurate value was proposed in 1901 by [[Friedrich Robert Helmert]] according to gravity measurements performed under the auspices of the [[International Association of Geodesy|International Geodetic Association]].<ref>{{Cite web|title=Clairaut's equation {{!}} mathematics|url=https://www.britannica.com/science/Clairauts-equation|access-date=10 June 2020|website=Encyclopedia Britannica|language=en}}</ref><ref name=":5">{{Cite journal |last=Perrier |first=Général |date=1935 |title=Historique Sommaire de la Geodesie |journal=Thalès |volume=2 |pages=117–129 |issn=0398-7817 |jstor=43861533}}</ref><ref name="The Shape of the Earth">{{Cite journal |last=Levallois |first=Jean-Jacques |date=May–June 1986 |title=L'Académie Royale des Sciences et la Figure de la Terre |trans-title=The Royal Academy of Sciences and the Shape of the Earth |url=https://gallica.bnf.fr/ark:/12148/bpt6k5470853s |journal=La Vie des Sciences |language=FR |volume=3 |page=290 |bibcode=1986CRASG...3..261L |access-date=4 September 2018 |via=Gallica}}</ref><ref>{{Cite book |last1=Delambre |first1=Jean-Baptiste (1749-1822) Auteur du texte |url=https://gallica.bnf.fr/ark:/12148/bpt6k110604s |title=Base du système métrique décimal, ou Mesure de l'arc du méridien compris entre les parallèles de Dunkerque et Barcelone. T. 1 / , exécutée en 1792 et années suivantes, par MM. Méchain et Delambre, rédigée par M. Delambre,... |last2=Méchain |first2=Pierre (1744-1804) Auteur du texte |date=1806–1810 |pages=10 |language=EN}}</ref><ref name="Earth-figure" /><ref>{{Cite web |last=von Struve |first=Friedrich Georg Wilhelm |date=July 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/bpt6k30026 |access-date=2021-08-30 |website=Gallica |page=509 |language=FR}}</ref><ref>{{Cite news |last=Viik |first=T |date=2006 |title=F. W. Bessel and geodesy |pages=10, 6 |work=Struve Geodetic Arc, 2006 International Conference, The Struve Arc and Extensions in Space and Time, Haparanda and Pajala, Sweden, 13–15 August 2006 |citeseerx=10.1.1.517.9501 |url=https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.517.9501}}</ref><ref>{{Cite journal |last1=Rath |first1=Geheimen |last2=Ritter |date=January 1842 |title=Ueber einen Fehler in der Berechnung der französischen Gradmessung und seinen Einfluss auf die Bestimmung der Figur der Erde |url=https://onlinelibrary.wiley.com/doi/10.1002/asna.18420190702 |journal=Astronomische Nachrichten |language=en |volume=19 |issue=7–8 |pages=97–116 |doi=10.1002/asna.18420190702 |issn=0004-6337}}</ref>

Significant improvements in gravity measuring instruments must also be attributed to Bessel. He devised a gravimeter constructed by [[Adolf Repsold]] which was first used in [[Switzerland]] by [[Emile Plantamour]], [[Charles Sanders Peirce]] and Isaac-Charles Élisée Cellérier (8.01.1818 – 2.10.1889), a [[Geneva]]n mathematician soon independently discovered a mathematical formula to correct [[Observational error|systematic errors]] of this device which had been noticed by Plantamour and [[Adolphe Hirsch]].<ref>{{citation-attribution|{{Cite book|url=http://www.rac.es/ficheros/Discursos/DR_20080825_173.pdf|title=Discursos leidos ante la Real Academia de Ciencias Exactas Fisicas y Naturales en la recepcion pública de Don Joaquin Barraquer y Rovira|last=Ibáñez e Ibáñez de Ibero|first=Carlos|publisher=Imprenta de la Viuda e Hijo de D.E. Aguado|year=1881|location=Madrid|pages=70–78}}}}</ref><ref>{{Cite journal |date=1880 |title=Rapport de M. Faye sur un Mémoire de M. Peirce concernant la constance de la pesanteur à Paris et les corrections exigées par les anciennes déterminations de Borda et de Biot |url=https://gallica.bnf.fr/ark:/12148/bpt6k3047v/f1457.image.r=1880%201880 |journal=[[Comptes rendus hebdomadaires des séances de l'Académie des sciences]] |volume=90 |pages=1463–1466 |access-date=2018-10-10 |via=[[Gallica]]}}</ref> This would allow [[Friedrich Robert Helmert]] to determine a remarkably accurate value of {{Sfrac|1/|298.3}} for the flattening of the Earth when he proposed his [[Earth ellipsoid|ellipsoid of reference]].<ref name="Enc. Universalis-1996">{{Cite book |title=Encyclopedia Universalis |publisher=Encyclopedia Universalis |year=1996 |isbn=978-2-85229-290-1 |pages=320, 370. Vol 10 |oclc=36747385}}</ref> This was also the result of the [[Metre Convention]] of 1875, when the metre was adopted as an international scientific unit of length for the convenience of continental European geodesists following forerunners such as [[Ferdinand Rudolph Hassler]] later [[Carl Friedrich Gauss]] and [[Carlos Ibáñez e Ibáñez de Ibero]].<ref name="Brunner-1857">{{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><ref name="Pérard-1957">{{Cite web |last=Pérard |first=Albert |date=1957 |title=Carlos Ibáñez e Ibáñez de Ibero (14 avril 1825 – 29 janvier 1891), par Albert Pérard (inauguration d'un monument élevé à sa mémoire) |url=https://www.academie-sciences.fr/pdf/eloges/ibanez_notice.pdf |website=Institut de France – Académie des sciences |pages=26–28}}</ref><ref>Adolphe Hirsch, ''Le général Ibáñez notice nécrologique lue au comité international des poids et mesures, le 12 septembre et dans la conférence géodésique de Florence, le 8 octobre 1891'', Neuchâtel, imprimerie Attinger frères.</ref><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><ref name="Clarke-1873">{{Citation |last=Clarke |first=Alexander Ross |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 |periodical=Philosophical Transactions |volume=163 |page=463 |year=1873 |place=London |doi=10.1098/rstl.1873.0014 |doi-access=free}}</ref><ref name="BEG-1868">{{Cite book |url=http://gfzpublic.gfz-potsdam.de/pubman/item/escidoc:108187:4/component/escidoc:272449/Generalbericht.mitteleurop%C3%A4ische.Gradmessung%201867.pdf |title=Bericht über die Verhandlungen der vom 30. September bis 7. October 1867 zu BERLIN abgehaltenen allgemeinen Conferenz der Europäischen Gradmessung |publisher=Central-Bureau der Europäischen Gradmessung |year=1868 |location=Berlin |pages=123–134 |language=german}}</ref><ref name=":3" />

The question of measurement reform was placed in the hands of the [[Academy of Sciences (France)|Academy of Sciences]], who appointed a commission chaired by [[Jean-Charles de Borda]]. Instead of the seconds pendulum method, the commission of the French Academy of Sciences – whose members included [[Jean-Charles de Borda|Borda]], [[Joseph-Louis Lagrange|Lagrange]], [[Pierre-Simon Laplace|Laplace]], [[Gaspard Monge|Monge]] and [[Marquis de Condorcet|Condorcet]] – decided that the new measure should be equal to one ten-millionth of the distance from the North Pole to the Equator (the quadrant of the Earth's circumference), measured along the meridian passing through Paris. Apart from the obvious consideration of safe access for French surveyors, the Paris meridian was also a sound choice for scientific reasons: a portion of the quadrant from Dunkirk to Barcelona (about 1000&nbsp;km, or one-tenth of the total) could be surveyed with start- and end-points at sea level, and that portion was roughly in the middle of the quadrant, where the effects of the Earth's oblateness were expected not to have to be accounted for. The expedition would take place after the [[Anglo-French Survey (1784–1790)|Anglo-French Survey]], thus the French meridian arc, which would extend northwards across the United Kingdom, would also extend southwards to Barcelona, later to [[Balearic Islands]]. [[Jean-Baptiste Biot]] and [[François Arago]] would publish in 1821 their observations completing those of Delambre and Mechain. It was an account of the length's variation of the degrees of latitude along the Paris meridian as well as the account of the variation of the seconds pendulum's length along the same meridian between [[Shetland]] and the Baleares.<ref name="gallica" /> Improvements in the measuring devices designed by Borda and used for this survey also raised hopes for a more accurate determination of the length of this meridian arc.<ref name="RNMF">{{Cite web |title=L'histoire des unités {{!}} Réseau National de la Métrologie Française |url=https://metrologie-francaise.lne.fr/fr/metrologie/histoire-des-unites |access-date=2023-10-06 |website=metrologie-francaise.lne.fr}}</ref><ref>{{Cite book |last1=Biot |first1=Jean-Baptiste (1774-1862) Auteur du texte |url=https://gallica.bnf.fr/ark:/12148/bpt6k1510037p |title=Recueil d'observations géodésiques, astronomiques et physiques, exécutées par ordre du Bureau des longitudes de France en Espagne, en France, en Angleterre et en Écosse, pour déterminer la variation de la pesanteur et des degrés terrestres sur le prolongement du méridien de Paris... rédigé par MM. Biot et Arago,... |last2=Arago |first2=François (1786-1853) Auteur du texte |date=1821 |pages=viii-ix |language=EN}}</ref><ref name="Débarbat-1799">{{Cite web |last=Suzanne |first=Débarbat |title=Fixation de la longueur définitive du mètre |url=https://francearchives.gouv.fr/fr/pages_histoire/39436 |access-date=2023-10-06 |website=FranceArchives |language=fr}}</ref><ref name="Levallois2">{{Cite web |last=Levallois |first=Jean-Jacques |date=1986 |title=La Vie des sciences |url=https://gallica.bnf.fr/ark:/12148/bpt6k5470853s |access-date=2019-05-13 |website=Gallica |pages=288–290, 269, 276–277, 283 |language=FR}}</ref><ref>{{Cite book |last=Capderou |first=Michel |url=https://books.google.com/books?id=jRQXQhRSrz4C |title=Satellites : de Kepler au GPS |date=2011-10-31 |publisher=Springer Science & Business Media |isbn=978-2-287-99049-6 |pages=46 |language=fr}}</ref><ref>{{Cite web |last=Ramani |first=Madhvi |title=How France created the metric system |url=http://www.bbc.com/travel/story/20180923-how-france-created-the-metric-system |access-date=2019-05-21 |website=www.bbc.com |language=en}}</ref><ref>Jean-Jacques Levallois, La méridienne de Dunkerque à Barcelone et la détermination du mètre (1792 – 1799), Vermessung, Photogrammetrie, Kulturtechnik, 89 (1991), 375-380.</ref><ref name="Levallois-19912">{{Cite journal |last=Zuerich |first=ETH-Bibliothek |year=1991 |title=La méridienne de Dunkerque à Barcelone et la déterminiation du mètre (1972-1799) |url=https://dx.doi.org/10.5169/seals-234595 |language=FR |pages=377–378 |doi=10.5169/seals-234595 |access-date=2021-10-12 |website=E-Periodica}}</ref><ref name="Martin-20082">{{Cite journal |last1=Martin |first1=Jean-Pierre |last2=McConnell |first2=Anita |date=2008-12-20 |title=Joining the observatories of Paris and Greenwich |url=https://royalsocietypublishing.org/doi/10.1098/rsnr.2008.0029 |journal=Notes and Records of the Royal Society |language=en |volume=62 |issue=4 |pages=355–372 |doi=10.1098/rsnr.2008.0029 |s2cid=143514819 |issn=0035-9149}}</ref>[[File:Reflecting circle-CnAM 1842-IMG 4998-gradient.jpg|left|thumb|[[Repeating circle]] devised by [[Jean-Charles de Borda]] and constructed by [[Étienne Lenoir (instrument maker)|Étienne Lenoir]]]]

After the [[French Revolution]], [[Napoleonic Wars]] led to the adoption of the metre in [[Latin America]] following [[Decolonization|independence]] of [[Empire of Brazil|Brazil]] and [[Hispanic America]], while the [[American Revolution]] prompted the foundation of the [[United States Coast and Geodetic Survey|Survey of the Coast]] in 1807 and the creation of the [[National Institute of Standards and Technology|Office of Standard Weights and Measures]] in 1830. During the mid nineteenth century, following the defeat and expulsion of [[Napoleon|Napoleon Bonaparte]]'s forces which brought an end to the short-lived [[French campaign in Egypt and Syria|French occupation of Lower Egypt]], the metre was adopted in [[Khedivate of Egypt]] an autonomusautonomous tributary state of the [[Ottoman Empire]] for the [[cadastre]] work.<ref>{{Cite book |last=Jamʻīyah al-Jughrāfīyah al-Miṣrīyah |url=http://archive.org/details/bulletindelasoc00almgoog |title=Bulletin de la Société de géographie d'Égypte |date=1876 |publisher=[Le Caire] |others=University of Michigan |pages=6–16}}</ref><ref>{{Cite book |last=texte |first=Ismāʿīl-Afandī Muṣṭafá (1825-1901) Auteur du |url=https://gallica.bnf.fr/ark:/12148/bpt6k840511v |title=Notes biographiques de S. E. Mahmoud Pacha el Falaki (l'astronome), par Ismail-Bey Moustapha et le colonel Moktar-Bey |date=1886 |pages=10–11 |language=EN}}</ref><ref>{{Cite book |last=texte |first=Ismāʿīl-Afandī Muṣṭafá (1825-1901) Auteur du |url=https://gallica.bnf.fr/ark:/12148/bpt6k62478474 |title=Recherche des coefficients de dilatation et étalonnage de l'appareil à mesurer les bases géodésiques appartenant au gouvernement égyptien / par Ismaïl-Effendi-Moustapha, ... |date=1864 |language=EN}}</ref> In [[continental Europe]], [[metrication]] and a better [[standardization]] of units of measurement respectively followed the successive fall of [[First French Empire]] in 1815 and [[Second French Empire]] defeated in the [[Franco-Prussian War]] (1870-1871). Napoleonic Wars fostered German nationalism which later led to [[Unificationunification of Germany]] in 1871. Meanwhile most European countries had adopted the metre. The 1870s marked the beginning of the [[Second Industrial Revolution|Technological Revolution]] a period in which [[German Empire]] would challenge Britain as the foremost industrial nation in Europe. This was accompanied by development in [[cartography]] which was a prerequisit for both military operations and the creation of the infrastructures needed for industrial development such as [[Rail transport|railways]]. During the process of [[unification of Germany]], geodesists called for the creation of a "European international bureau for weights and measures".<ref>{{Cite book |last1=Alder |first1=Ken |title=Mesurer le monde: l'incroyable histoire de l'invention du mètre |last2=Devillers-Argouarc'h |first2=Martine |date=2015 |publisher=Flammarion |isbn=978-2-08-130761-2 |series=Libres Champs |location=Paris |pages=499–520}}</ref><ref name="BEG-1868" />

The [[Metre Convention]] was signed on 20 May 1875 in Paris and the [[International Bureau of Weights and Measures]] was created under the supervision of the [[International Committee for Weights and Measures]]. At the session on 12 October 1872 of the Permanent Committee of the International Metre Commission, which was to become the [[General Conference on Weights and Measures|International Committee for Weights and Measures]], Carlos Ibáñez e Ibáñez de Ibero had been elected president.<ref name="MComm" /><ref name="BIPMhist">{{citation |title=The BIPM and the evolution of the definition of the metre |url=http://www.bipm.org/en/measurement-units/history-si/evolution-metre.html |access-date=30 August 2016 |publisher=[[International Bureau of Weights and Measures]]}}</ref><ref name="IAG-history">{{Cite web |title=A Note on the History of the IAG |url=http://www.iag-aig.org/index.php?tpl=text&id_c=80&id_t=143 |access-date=19 September 2018 |website=IAG Homepage}}</ref><ref>{{Cite journal |last=Torge |first=W. |date=1 April 2005 |title=The International Association of Geodesy 1862 to 1922: from a regional project to an international organization |journal=Journal of Geodesy |language=en |volume=78 |issue=9 |pages=558–568 |bibcode=2005JGeod..78..558T |doi=10.1007/s00190-004-0423-0 |issn=1432-1394 |s2cid=120943411}}</ref><ref>{{Cite book |url=https://play.google.com/books/reader?id=XktTAAAAcAAJ&hl=fr&pg=GBS.PA153 |title=Procès-verbaux: Commission Internationale du Mètre. Réunions générales de 1872 |date=1872 |publisher=Imprim. Nation |pages=153–155 |language=fr}}</ref> His presidency was confirmed at the first meeting of the International Committee for Weights and Measures, on 19 April 1875. Three other members of the committee, the German astronomer, [[Wilhelm Julius Foerster]], director of the [[Berlin Observatory]] and director of the German Weights and Measures Service, the Swiss [[meteorologist]] and [[physicist]], [[Heinrich von Wild]] representing Russia, and the Swiss geodesist of German origin, Adolphe Hirsch were also among the main architects of the Metre Convention.<ref name=":3">{{Cite journal |last1=Débarbat |first1=Suzanne |last2=Quinn |first2=Terry |date=1 January 2019 |title=Les origines du système métrique en France et la Convention du mètre de 1875, qui a ouvert la voie au Système international d'unités et à sa révision de 2018 |journal=Comptes Rendus Physique |series=The new International System of Units / Le nouveau Système international d’unités |language=fr |volume=20 |issue=1 |pages=6–21 |bibcode=2019CRPhy..20....6D |doi=10.1016/j.crhy.2018.12.002 |issn=1631-0705 |doi-access=free}}</ref><ref>{{Cite book |last=COMITÉ INTERNATIONAL DES POIDS ET MESURES. |url=https://play.google.com/store/books/details?id=QgkAAAAAMAAJ |title=PROCÈS-VERBAUX DES SÉANCES DE 1875-1876. |publisher=Gauthier-Villars |year=1876 |location=Paris |pages=3}}</ref><ref name=":0">{{Cite book |last=COMlTÉ INTERNATIONAL DES POIDS ET MESURES. |title=PROCÈS-VERBAUX DES SÉANCES. DEUXIÈME SÉRIE. TOME II. SESSION DE 1903. |publisher=GAUTHIER-VILLARS |year=1903 |location=Paris |pages=5–7}}</ref> In the 1870s, [[German Empire]] played a pivotal role in the unification of the metric system through the [[International Association of Geodesy|European Arc Measurement]] but its overwhelming influence was mitigated by that of neutral states. While the German astronomer [[Wilhelm Julius Foerster]] alongsidealong with the Russian and Austrian representatives boycotted the Permanent Committee of the International Metre Commission in order to prompt the reunion of the [[Metre Convention|Diplomatic Conference of the Metre]] and to promote the foundation of a permanent [[International Bureau of Weights and Measures]], [[Adolphe Hirsch]], delegate of Switzerland at this Diplomatic Conference in 1875, conformed to the opinion of Italy and Spain to create, in spite of French reluctance, the International Bureau of Weights and Measures in France as a permanent institution at the disadventagedisadvantage of the [[Conservatoire national des arts et métiers|''Conservatoire national des Arts et Métiers'']].<ref name=":0" /><ref>{{Cite web |date=30 March 1875 |title=Bericht der schweizerischen Delegierten an der internationalen Meterkonferenz an den Bundespräsidenten und Vorsteher des Politischen Departements, J. J. Scherer in Erwin Bucher, Peter Stalder (ed.), Diplomatic Documents of Switzerland, vol. 3, doc. 66, dodis.ch/42045, Bern 1986. |url=https://dodis.ch/42045 |website=Dodis}}</ref><ref>{{Cite journal |last=Quinn |first=Terry |date=May 2019 |title=Wilhelm Foerster's Role in the Metre Convention of 1875 and in the Early Years of the International Committee for Weights and Measures |url=https://onlinelibrary.wiley.com/doi/10.1002/andp.201800355 |journal=Annalen der Physik |language=en |volume=531 |issue=5 |doi=10.1002/andp.201800355 |issn=0003-3804|doi-access=free |bibcode=2019AnP...53100355Q }}</ref>