74 History of Astroywmij for the Year 1 806. 



moirs, one of which is upon the annual parallax of the Lyre, 

 which he finds as at 4*4'"; another upon the opposi^foM /o 

 the planet Herschel 1805, and a third upon the elements of 

 its orbit. The rest are ^lpon the eclipse of the Sun in 1806, 

 observed at Rome and Padua, and calculated by M. Conti ; 

 upon the method of corresponding altitudes; and, finally, a 

 nonagesimal tabic for the latitude of Rome. 



The parallax of 4*4" would reduce the distance of the Lyre 

 to ICOO millions of leagues in place of 7000 ; but as the pa.- 

 rallax of right ascension of the Lyre varies much more than 

 the parallax of declination, it is to be wished that this me- 

 thod were employed for clearing up this curious question. 



The greatest parallax of the Lyre in right ascension is be- 

 tween the end of May and the end of September; in de- 

 clination, between the end of June and the cud of Deceniber; 

 and as "it was towartls the n)onth of August that it was most 

 observed passing the meridian at cighl o'clock, it is possible 

 that the difierence may have escaped the most exact ob- 

 servers. 



The prolpngaticn of our meridian; undertaken this year, 

 cannot fail to be interesting to astronomers. We therefore 

 thiuk it our duly to apprise them in what state it is, and to 

 assure them of the certainty soon completely succeeding. 



Since the 2d of May M. de Laplace proposed to continue 

 the meridian to the Balearic islands. Messrs. Biot, Arrago, 

 and Rodriguez the Spanish philosopher, set out with instru- 

 ments on the 2d of September. 



During M. Arrago's absence his place is filled in the ob- 

 servatory by M. Cldiide Louis Mathicu, born at Macon in 

 November 1784, who is well skilled in astronomical ob- 

 servations and calculations. 



As they were also to determine the pendulum at 45", on 

 the 26ih of July Messrs. Rouvard and Biot put in trial the 

 invariable pendulum of platina intended to be carried i:ito the 

 different points of the meridian. In order to deduce the 

 simple pendulum from it, and the.variations in gravity, they 

 made it oscillate before the pendulum of a clock, the pace 

 of which was perfectly well known, and they observed from 



a distance. 



