1^6 Hi/iorj! of Jj}ron077iy for the Ytar iSo-J. 



The mean of four hundred obfervations gives 23° 28'' Y't ^^ 

 ')" mure than in my tables: la ft year it was only 6" ; \ve 

 ought to be falisfied with this agreement. 



Duc-Ia-Chapclle has publidied, in the fourth volume of 

 the Memoirs of the Inllitutc, folllitial obfervations which 

 give him 31'' for the fccular dimiuution of the obliquity of 

 the ecliptic. C. Mechaiii has ftill found 10 feconds lefs for 

 the oblicjuity of the winter lolltice. 



C. Vidal has fent in his obfervations of the new planets 

 and a srreal many others: he has even luid the complaifance 

 to terminate fome zones of circumpolar ftars which were not 

 complete in the Hijhnre Cclcjie Frayn-ofc publiflied in 1801. 



'I'he inferior conjunrtion of Venus, obi'erved in the end of 

 December bv C. Burckhardt and Lalande, gave us for the 

 correction of my tables + 29', which do not make to in 

 the longitude feen from the fun. 



But as the tables of Venus had not vet been calculated with 

 the perturbations, and as C. Lalande junior propofed to un- 

 dertake this labour, C. Chabrol furniflied him with a table 

 of the equation calculated to tenths of feconds, which was an 

 elTcntial |Meliininarv. It is tim.e it fliould be begun. We have 

 40 years exaiSl obfervations ot Venus ; and thefe 40 years ob- 

 fijrvations, from 1761 to 1801, will give us the motion of 

 \"enus as exa6t as the Babylonian oblervation made 2072 

 vears ago, and refpcfting which there is fome doubt, as I 

 have already explained. (See Mcmoires de l' Acadetjiie 1785, 

 p. 250.) 



The oppofition of Mars, which took place on the 24th of 

 December, could not be obferved ; but the obfervations of 

 that night gave a correction in the tables of Lalande junior 

 — 5"; which make only two in the heliocentric longitude. 



The difappearance of Saturn's ring, which will take place 

 in 1803, has been preceded bv a fmgular phasnomenon. The 

 anfes were on the point of difappearing, and it was with dif- 

 ficulty that C. Mechain difcovcred them on the morning of 

 December xo. C. Flaguergues alfo loft fight of them on the 

 16th. But we ftiall foon fee them re-appear, as the earth will 

 return on the 28th of June: the fun paffing through the plane 

 of the ring, we (hall lofe fight of them till the 23d of Au- 

 guft, at which time the earth will pafs to the north of the 

 ring, and permit us to fee the fiirfaceof it illuminated by the 

 fun. Dujejour, Traite analytique des WLonvemms dlejlesy 

 vol. ii. p. 155. 



C. Chabrol and C. Flaguergues have calculated a great 

 ntiniber of tables of aberrations and nutations for 600 ftars 

 of the fundamental catalogue which Lalande junior inferts 



every 



