8 tl'ijlory of AJh^monty for the Y^dt 1 80o. 



longifnde and 6 in latitude ; and the obfervation made by 

 ■ Bouvard with the new inftrnments of the obfervatory, gav6 

 the lame number of feconds ; which confirms, in a fatisfac- 

 tory manner, the goodnefs of our inftrumehts and the exa£t- 

 nefs of our bbfervers. 



Tricfnccker has undertaken a iimilar labour at Vienna, 

 "and Oriani at Milan. The differences are infenfible, but 

 none of the three knew any thing of what was doing by hi** 

 fellow-labourers. ^ - 



Wurm has alfo calculated the perturbations of Mars by 

 the method of Klugel, inferted in the memoirs of the Society 

 of Gottingen. Oriani, Buvckhardt, Schubert, and Wurm, 

 do not always agree, but the differences are trifling. 



Bouvard is employed in calculating the perturbations of 

 all the planets, as they affect each other, by the formulae of 

 De Laplace. This will be a very complete work, the refult 

 of which will appear in the fecond volume of the Mecanique 

 Celefte, 



The tranfit of Mercury over the fun has afforded me an 

 opportunity of verifying the place of the aphelion by the 

 method which I gave in the memoirs of the Academy for 

 1786, and which is the moft conclufive. By my refult it' 

 apjuars that there is no reafon for making any change in the 

 tables of Mercury, which I publifhed in the Connoijfance des 

 Temps, The fame agreement in regard to Venus may be 

 feen in the Connoijpmce des Temps for the year ii, p. 4564 



For Jupiter we have found the corre6lion to be made in 

 rtie tables -|- 34'/ in the cppofuion and 4- 30" in the qua- 

 drature. 



For Saturn the correftion in the oppofition is — 10'', 

 nearly as the preceding year. 



For Herfchers planet I have found — 9'^ ; and Von Zaeh,' 

 by employing five obfervations, had the fame refult. 



We have reafon therefore to be fatisfied with the cor- 

 re^lnefs of our tables for all the planets. 



In regard to the tables of the fun, T have flill found 8 or 

 10^^ too much in our longitudes : whether this arifes from a 

 retardation in the motiow of the earth for 15 or 20 years paft^ 

 or from fume error rcrpt<fting the mean motion in the con-f 



liru6lbr» 



