Jean Baptiste Joseph, chevalier Delambre was a French mathematician, astronomer, historian of astronomy, and geodesist. He was also director of the Paris Observatory, and author of well-known books on
Delambre Boilly crop
Histoire de l'astronomie ancienne, 1817
Title page of an 1817 copy of "Tables écliptiques des satellites de Jupiter"
1817 copy of "Tables écliptiques des satellites de Jupiter"
History of the metre
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During the French Revolution, the traditional units of measure were to be replaced by consistent measures based on natural phenomena. As a base unit of length, scientists had favoured the seconds pend
Jean Baptiste Joseph Delambre
…Delambre analogies History of the metre Arc measurement of Delambre and Méchain…
Replicas of historical metric standards, including an iron copy of the mètre des Archives.
A copy of the "provisional" metre located in the wall of a building, 15 rue de Vaugirard, Paris.
Closeup of National Prototype Metre Bar No. 27, made in 1889 by the International Bureau of Weights and Measures (BIPM) in collaboration with Johnson Mattey and given to the United States, which served as the standard for American cartography from 1890 replacing the Committee Meter, an authentic copy of the Mètre des Archives produced in 1799 in Paris, which Ferdinand Rudolph Hassler had brought to the United States in 1805.
A Krypton-86 lamp used to define the metre between 1960 and 1983