Jean Baptiste Joseph, chevalier Delambre (19 September 1749 – 19 August 1822) was a French mathematician,astronomer,historian of astronomy, andgeodesist.[1][2] He was also director of theParis Observatory, and author of well-known books on the history ofastronomy from ancient times to the 18th century.
After a childhood fever, he suffered from very sensitive eyes, and believed that he would soon go blind. For fear of losing his ability to read, he read any book available and trained his memory. He thus immersed himself in Greek and Latin literature, acquired the ability to recall entire pages verbatim weeks after reading them, became fluent in Italian, English and German and even wrote an unpublishedRègle ou méthode facile pour apprendre la langue anglaise (Easy rule or method for learning English).
Delambre quickly achieved success in his career in astronomy, such that in 1788, he was elected a foreign member of theRoyal Swedish Academy of Sciences. In 1790, to establish a universally accepted foundation for the definition of measures, theNational Constituent Assembly asked theFrench Academy of Sciences to introduce a new unit oflength. The academics decided on themetre, defined as 1 / 10,000,000 of the distance from the North Pole to the equator, and prepared to organise an expedition to measure the length of themeridian arc betweenDunkirk andBarcelona. This portion of themeridian, which also passes through Paris, was to serve as the basis for the length of the quarter meridian, connecting theNorth Pole with theEquator. In April 1791, the academy's Metric Commission confided this mission toJean-Dominique de Cassini,Adrien-Marie Legendre andPierre Méchain. Cassini was chosen to head the northern expedition but, as a royalist, he refused to serve under the revolutionary government after the arrest of KingLouis XVI on hisFlight to Varennes. On 15 February 1792, Delambre was elected unanimously a member of theFrench Academy of Sciences and in May 1792, after Cassini's final refusal, was placed in charge of the northern expedition, measuring the meridian from Dunkirk toRodez in the south of France.Pierre Méchain headed the southern expedition, measuring from Barcelona to Rodez. The measurements were finished in 1798. The gathered data were presented to an international conference of savants in Paris the following year.
After Méchain's death in 1804, he was appointed director of theParis Observatory. He was also professor of astronomy at theCollège de France. The same year he married Elisabeth-Aglaée Leblanc de Pommard, a widow with whom he had lived already for a long time. Her son, Achille-César-Charles de Pommard (1781–1807) assisted Delambre on several occasions in his astronomical andgeodetical surveys, notably the measuring of the baselines for the meridian survey, and the latitude definition for Paris in December 1799 which was presented to the Conference of Savants.
Notice historique sur M. Méchain, lue le 5 messidor XIII (Baudouin, Paris, January 1806; this is the eulogy on the late Pierre Méchain, read at the academy by Secretary Delambre on 24 June 1805)
A history of astronomy, comprising four works and six volumes in all:
Histoire de l'astronomie ancienne, Paris: Mme Ve Courcier, 1817. 2 volumes; vol. 1, lxxii, 556 pp., 1 folded plate; vol. 2, viii, 639 pp., [1], 16 folded plates.OCLC490232972. Reprinted by New York and London: Johnson Reprint Corporation, 1965 (Sources of Science, #23), with a new preface by Otto Neugebauer.OCLC648488. Text on line: vol. 1,[1],[2],[3]; vol. 2,[4],[5].
Histoire de l'astronomie du moyen age, Paris: Mme Ve Courcier, 1819. lxxxiv, 640 pp., 17 folded plates.OCLC490233042. Reprinted by New York and London: Johnson Reprint Corporation, 1965 (Sources of Science, #24.)OCLC647834. Also reprinted by Paris: J. Gabay, 2006.OCLC494627038. Text on line:[6].
Histoire de l'astronomie moderne, Paris: Mme Ve Courcier, 1821. 2 volumes; vol. 1, lxxxii, 715 pp., [1], 9 folded plates; vol. 2, [4], 804 pp., 8 folded plates.OCLC490233154. Reprinted by New York and London: Johnson Reprint Corporation, 1969 (Sources of Science, #25), with a new introduction and tables of contents by I. Bernard Cohen.OCLC647838. Also reprinted by Paris: Editions Jacques Gabay, 2006.OCLC493779358. This takes the history to the 17th century. Text on line: both volumes, with usable plates,[7]; vol. 1,[8],[9],[10]; vol. 2,[11].
Histoire de l'astronomie au dix-huitième siècle, edited by Claude-Louis Mathieu, Paris: Bachelier (successeur de Mme Ve Courcier), 1827. lii, 796 p., 3 folded plates.OCLC490233264 Reprinted by Paris: J. Gabay, 2004.OCLC470502171. This includes the history of astronomy in the 18th century, especially critiques of his colleagues at the academy, which he withheld to be published posthumously. Text on line:[12]; with usable plates,[13].
^George William Foote, ed. (1887). Progress: a monthly magazine of advanced thought, Volume 7. Progressive Publishing Co. p. 127. DELAMBRE (Jean Baptiste Joseph), French astronomer, born at Amiens, 19 September 1749, studied under Lalande and became, like his master, an Atheist.
Ken Alder:The Measure of All Things – The Seven-Year Odyssey and Hidden Error That Transformed the World (The Free Press; New York, London, Toronto, Sydney, Singapore; 2002;ISBN0-7432-1675-X)
A brief biography of Delambre, partly from the 1880 Encyclopædia Britannica, including an account of Delambre's intervention to request liberation (from French imprisonment) of James Smithson, who went on to endow the foundation of the Smithsonian Institution, national museum of the United States of America
Media related toJean-Baptiste Joseph Delambre at Wikimedia Commons
