Bigourdan, Camille Guillaume

(b. Sistels, Tarn-et-Garonne, France, 6 April 1851; d. Paris, France, 28 February 1932)

astronomy, history of science.

Bigourdan was born to a peasant family from the Bigorre (whence his surname) and from them inherited his passion for work, his strong character, and his deep religious convictions. His teacher, Félix Tisserand, introduced him to the study of astronomy in Toulouse, and in 1879 summoned him to the Paris Observatory, where Bigourdan was astronomer-in-chief from 1897 to 1925. He was a member of the Bureau des Longitudes (1903), of the Académie des Sciences (1904), and, for his work in meteorology, of the Académie d’Agricultltre (1924).

Bigourdan was a remarkable observer, and most of his contributions to astronomy were visual surveys of position: meridian observations and equatorial observations of double stars, asteroids, comets, and especially nebulae. He also perfected instruments and methods. His catalog of the positions of 6,380 nebulae brought him the gold medal of the Royal Astronomical Society in 1919.

His work has been made partially obsolete by technical progress, but his studies on time and the history of astronomy are still of value. After serving as a promoter, with Gustave Ferrié, of the International Congress on Time (1912), Bigourdan became the director of the Bureau International de l’Heure when it was created in 1919. He deliberately oriented this originally technical agency toward science. His emphasis on science, although it led to his dismissal in 1929, greatly benefited astronomy.

Moreover, Bigourdan left numerous authoritative historical studies. He also discovered various lost manuscripts, particularly those of the French astronomer J. A. G. Pingré, which allowed him to publish his Annales célestes du XVII^esiècle in 1901.

BIBLIOGRAPHY

I. Original Works. Bigourdan’s astronomical works include “Sur l’équation personnelle dans les mesures d’étoiles doubles” (doctoral thesis, 1886), in Annales de l’Observetoire de Paris (Mémories), 19 (1889), C1-C74; Observations de nèbuleuses et d’amas stellaires, 1884–1909, 6 vols. (Paris, 1899–1917); “Détermination de la différencede longitu de entre les méridiens de Greenwich et de Paris, exécutée en 1902,” written with F. Lancelin, in Annales de l’Observatire de Paris (Mémoires), 26 (1910), B1-B214; and Gnomonique ou Traité théorique et pratique de la construction des cadrans solaires (Paris, 1921).

In the history of science Bigourdan published Le système métrique des poids et mesures (Paris, 1901); De l’origine à la formation de l’Observatoire de Paris, Vol. I pf Histoire de l’astronomie d’observation et des observatories en France(Paris, 1918); “Un institut d’optique à Pari. au XVIII^e siècle,” in Comptes rendus du Congrès des Sociétés Savantes en 1921, Sciences (Paris, 1922), pp. 19–74; and De la fondation de l’Académie à la fin du XVIII^e siècle, Vol. II of Histoire de l’astronomie de l’observation et des observatoires en France (Paris, 1930).

His articles in the Bulletin astronomique include “Honoré Flaugergues, sa vie et ses travaux,” in 1 (1884), 569–576, and 2 (1885), 151–156, 491–500; “Histoire des observatoires de l’École Militaire,” in 4 (1887), 497–504, and 5 (1888), 30–40; and “La prolongation de la méridienne de Paris, de Barcelone aux Baléares, d’après des correspondances inédites de Méchain, de Biot et d’Arago,” in 17 (1900), 348–368, 390–400, 467–480.

Articles in the Annuaire du Bureau des Longitudes are “Le jour et ses divisions” (1914), B1-B107; “Le calendrier babylonien” (1917). A1-A20; “Le calendrier égyptien” (1918), A1-A42; “Les comètes, liste chronologique de celles qui ont paru depuis l’origine à 1900” (1927), A1-A76; and “Le Bureau des Longitudes. Son histoire et ses travaux depuis l’origine (1795)” (1928), A1-A72; (1929), C11-C92;(1930), A1-A110; (1931), A1-A151; (1932), A1-A117; and (1933), A1-A91.

II. Secondary Literature Works on Bigourdan are A. Collard, “L’astronome G. Bigourdan, “in Ciel et terre, 48 (1932), 165–167; F. W. Dyson, “G. Bigourdan,” in Monthly Notices of the Astronomical Society, 93 (1933), 233–234; and P. A. MacMahon, “Address… on the Award of the Gold Medal…to G. Bigourdan,” ibid., 79 (1919), 306–314.

Jacques R. Levy