Astronomy. 179 



tical elements that have been calculated for it. M. Hansen has computed 

 a second elliptic orbit for it, which is as follows : 



Mean Time. 

 Passage of Perihelion at Seeberg, 1825, Dec. 11, 29767 



Longitude of Node, f Mean Equinox, » 215° 39' 17".? 



Log. of Node,— Long. Perihelion, \ 1st September, J 257 24 3.2 

 Inclination of Orbit, . . - 33 35 9.5C 



Eccentricity, - . . 0.9817028 



0.0923926 

 Revolution, - - 556 Years. 



Motion, Retrograde. 



On the 3d of June, at 8 h 54' mean time at Seeberg, this comet will be 

 in 201° 41' right ascension, and 15° 08' south declination, and its distance 

 from the earth will be 1.713. 



6. First Comet of 1826, or the lost Comet of 1772.— This comet, discover- 

 ed by M. Biela on the 27th February, and by M. Gambard on the 9th 

 March, has been found by M. Clausen to be the comet of 1805, and also 

 that o/1772, which has been so long lost sight of. He has found its ellip- 

 tical elements to be as follows : 



Mean Time. 

 Passage of Perihelion at Altona, 1826, March 18, 49297 

 Longitude of Perihelion, f Mean Equinox, ) 109* 53' 29".7 



Longitude of Node, \ Jan. 0. 1826, J 251 27 19.9 



Log. Perihelion Distance, .... 0.5496086 



Eccentricity. . . = Sun. (48° 12' 28*75) 



Inclination of Orbit, . . . 13 32 52 



Revolution, - . . 2438 Days. 



Motion, Direct 



It is necessary only to suppose a revolution of 2470 days to establish 

 the identity of this comet with that of 1772. We should then have five re- 

 volutions between 1772 and 1805, and three revolutions between 1805 and 

 1826. 



M. Gauss has proved that the comet of 1772 cannot be identical with 

 that of 1805 ; at least, that between its two oppositions, it has not passed 

 near so large a planet, that it could have experienced from it such perturba- 

 tions as would explain the difference between its elements at the two op- 

 positions. But this is precisely the difficulty that the elements of M. 

 Clausen satisfactorily explains, after a remark of Dr Olbers. By supposing 

 the comet of 1772 to have a revolution of 2438 days, it ought to have been 

 exposed in 1782, and still more in 1794, during a considerable time, to the 

 powerful influence of Jupiter. In order to estimate this influence, M. 

 Clausen is at present examining anew the ancient observations, and com- 

 puting the perturbations — Letter from Professor Shumacher, March 30, 

 1826. 



7. Ellipticity of the Earth at Port Bowen. — It appears from observa- 

 tions made with an invariable pendulum at Greenwich and at Port Bowen 

 in the Arctic regions, that the ellipticity of the earth is 35^=-. 



