GOULD — REDUCTION OF D AGELET S OBSERVATIONS. 6 



Joseph LePaute d'Agelet was born at Thonne la Long, near Montmedi, near the frontier 

 of Luxemburg', and in the present department of the Meuse, on the 25th of November, 1751, 

 the son of Pierre LePaute and Martine de Mouzon, and the nephew of the two LePautes 

 so eminent as makers of chronometers and astronomical clocks. Madame LePaute, whose 

 astronomical computations and services as assistant to Lalande are so well known, was the 

 wife of the elder of these brothers, and invited her nephew, the young d'Agelet, soon after 

 the completion of his sixteenth year, to come to Paris as the pupil of Lalande, who was then 

 at the observatory of the College Mazarin. Here he remained for five years, winning the 

 respect, confidence, and attachment of Lalande by his talent, fidelity, and amiable character, 

 until in March, 1773, he was appointed astronomer to the southern naval expedition of Ker- 

 guelen. On this expedition he made extensive observations of longitudes, tides, magnetic 

 variations, and collected many valuable specimens of natural history, but was disappointed in 

 the want of opportunity for further astronomical and geographical determinations. In August, 

 1771, he returned to Paris and resumed his astronomical pursuits. 



In 1777 d'Agelet was appointed Professor of Mathematics at the Ecole Militaire. His pre- 

 decessor, Jeaurat, had, in 17G8, prevailed upon the Due de Choiseul, Minister of War, to 

 establish an Observatory at this institution ; and a large wall had been built, adapted for the 

 possible reception of a mural quadrant. Lalande states 1 that he exerted himself for a long 

 time in vain, to obtain an appropriation for the purchase of the desired instrument. " Je 

 disais ce que la loi dit de la pierre d'attente, perpetuo damans, et je ne m'y suis pas trompe. 

 Apres avoir fait des efforts inutiles aupres des ministres les plus celebres et les plus savants, 

 Malesherbes et Turgot, pour avoir son mural, je 1'obtins en 1774 de Bergeret, receveur- 

 general des finances. On voit dans l'Evangile que le publicains fit honte au pharisien." The 

 instrument was ordered of Bird, in London, and seems to have been essentially a copy of the 

 one which he had made for Bradley a quarter of a century before. The instrument was 

 mounted 1778, August 23, and d'Agelet began at once a series of regular observations, both 

 planetary and stellar. In 1780 he had already 1,600 observations of planets, and a much 

 larger number of fixed stars, of which, at Lalande' s instance, he proposed preparing an exten- 

 sive catalogue. In April, 1782, he received the second nomination to the Academy of Sciences, 

 and in January, 1785, was unanimously elected a member. Observations of planets made by 

 him with the quadrant may be found in the Memoirs of the Academy for 1784, 1785, 1786. 

 The fourth volume of Lalande' s Astronomy, published in 1781, and the eighth volume of his 

 Epliemerides, published in 1783, contain a large number ; and Lalande alleges 2 that no one in 

 Europe was then doing so much for astronomy as d'Agelet. 



In 1782 he commenced observing faint stars, although, as before mentioned, his earliest 

 published observations of this sort date from February, 1783. 



When, in 1785, King Louis XVI formed the plan of a French scientific expedition round 

 the world, analogous to those of Cook, La Perouse was placed in command, and no pains 

 were spared to obtain the best men that could be found. D'Agelet was the youngest astrono- 



Conn. des Temps, An VI, 441 ; Hist, Cel., p. ii, Mem. de l'Acad., 1769, p. 187. 2 Conn, des Temps, An VI, 442. 



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