REDUCTION 



OF THE 



OBSERVATIONS OF FIXED STARS 



MADE 



By JOSEPH LEPAUTE D'AGELET, AT PARIS, IN 1783—1785, 



WITH A 



CATALOGUE OF THE CORRESPONDING MEAN PLACES, REFERRED TO THE EQUINOX OF 1800.0, 



BY 



BENJAMIN APTHORP GOULD. 



} 1. PRELIMINARY. 



The Histoire Celeste Frangaise of Lalande, published in 1801, contains, on pages 481-566, 

 a copy of the rough notes or day-book of observations of fixed stars made by the astronomer 

 d' Agelet at the Military School of Paris, between the 18th February and the 25th September, 

 1783. Lalande had previously published, in the Memoirs 1 of the French Academy of Sciences 

 for 1789, a series of similar observations made by d' Agelet between March 22 and October 2, 

 1784 ; and in the Memoirs 9 for 1790 another series still, comprising observations made between 

 October 6, 1784, and April 29, 1785 ; and he states 3 that when d' Agelet left Paris in Juno, 

 1785, with the unfortunate expedition of La Perouse, he deposited with him the original 

 manuscripts on bidding farewell, obtaining at the same time a promise that they should be 

 published in case their author should not return. 



In various places 4 Lalande farther informs us that a large number of observations of fixed 

 stars had been made between 1778 and 1780, and that d' Agelet had begun to observe small 

 stars, previously too much neglected by astronomers, in the month of September, 1782. But 

 although the last page of the Histoire Celeste contains a promise of a subsequent publication 

 of observations made prior to those contained in that volume, it is stated on page 479 that 

 1783, February 18, the earliest date there given, was the first day of regular observations 

 upon small stars. It seems, therefore, beyond reasonable doubt that the three series, referred 

 to, contain all the observations of small stars made by d' Agelet, and this is rendered more 

 certain by Lalande' s declaration 5 that he had fulfilled his promise of publishing these obser- 

 vations. 



1 Mem. de l'Acad., 1789, pp. 641—662. 3 Conn. d. Temps, An. VI, p. 446. * Conn. d. Temps, An. VI, pp. 442-3. 



3 Mem. do l'Acad., 1790, pp. 633—658. Mem. do l'Acad., 1784, p. 74. 6 Histoire Celeste, p. 479. 



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