Hi/lory of Ajlrommy Jgy the Year 1799. 37 



eccentricity of that planet, were found to corrcfpond with 

 my tables, except a few feconds. 



The inferior conjiiutliou of Venus, on the 1 6th of Octo- 

 ber 1799, was a phenomenon alfo of importance for the 

 theory of this planet. It takes place only every eight years 

 in that part of her orbit. It was obferved with as much 

 affiduity as fuccefs by C. Lefran^ais and Burckhardt, in my 

 obfervatory at the Maijhn du Champ de Mars. I have com- 

 pared it with that of 1751, which was in the fame pofition, 

 and for which I had made a great number of calculations, 

 and I have found fcarcely any thing to be changed in the 

 elements which ferved for the conftruftion of my tables of 

 Venus, publifhed in the third edition of my Aftronomy in 

 1792. This labour will be inferted in the Memoirs of the 

 Inltitute. 



On the 23d of November this beautiful planet was eclipfed 

 by the moon. This phenomenon would have attrafted a 

 number of eyes, had it not been at four o'clock in the morn- 

 ing, Jupiter, which is not fo brilliant, drew together a 

 great crowd at the Palais Royal, on the 14th of March 1788^ 

 to fee him on the point of being eclipfed. 



Obfervations of Jupiter have proved that about 30 ''are to 

 be added to the tables, which fhews that we ought to make 

 a little addition to the mean motion : this I before proved in 

 difcuffing the ancient obfervations in the Almageft of Pto- 

 lemy. The oppofition of the 16th December 1799 gave 

 me 30 feconds. C. Quenot, an able navigator, who has re- 

 turned from Egypt, obferved it with an aftronomical circle, 

 and obtained the fame refult. The latitude alfo was found 

 too fmall by 15"; from which I conclude, that the longitude 

 of the node of Jupiter, which is in the tables of C. Delam- 

 bre, in the third edition of my Aftronomy, ought to be dimi- 

 fiifhed 10'. 



The tables of Mars are thofe moft deficient. C. Lefran- 

 ?ais, therefore, has been employed on them for fome months. 

 He has calculated all the oppofitions and quadratures hitherto 

 obferved with accuracy, and the refult will be tables more ac- 

 curate than any ever yot given, in whicli there will be only a 

 few feconds of uncertainty. C. Burckhardt has calculated the 



perturbations 



