DELAMBRE, JEAN BAPTISTE JOSEPH, a French astronomer, was h. at Amiens, 19th Sept., 1749, and studied first under Delisle, and afterwards under Lalande, with both of whom he formed a close friendship. The discovery of the planet Uranus, in 1781, gave him the first opportunity of attracting the attention of the learned world in general. He formed tables of its motion, which obtained the annual prize of the academy of sciences. Soon after, he commenced the construction of new solar tables, and, at a still later period, tables of the motions of Jupiter and Saturn. Along with Mechain, he was appointed by the French government, in 1792, to measure the arc of the meridian between Dunkirk and Barcelona, which was completed in 1799. After wards, he was elected member of the academy. In 1802, he was appointed inspector general of education, and in 1803, perpetual secretary of the mathematical section of the institute. The result of his measurements appeared in his great work, Base du
Systeme Metrigue Decimal (1806-10). In 1807, he obtained the chair at the college of France, rendered vacant by the death of Lalande, his master and friend. In 1814, he was appointed a member of the council of public instruction. He died at Paris, 19th Aug., 1822. D. received a multitude of honors during his lifetime. He was a member of most of the learned bodies in Europe, an officer of the legion of honor, and a chevalier of the order of St. Michael. His writings are very numerous. The principal are: Traite d' Astrononzie (Paris, 1814); Ilistoire de l'Astronomie du Noon Age (Paris, 1819); Histoire de l' A stronornie Moderne (1821); and Ilistoire de l' Astronamie au Diz-Iruitieme Siecle (Paris, 1823-27), published under the care of Matthieu. Besides these, D. wrote several excel lent Mentoires.