Astronomical Society/. 141 



posed was the comet announced by M Gambart. Looking for the 

 same comet on subsequent evenings, the only one of his instru- 

 ments through which it was visible, was an achromatic telescope 

 whose double object-glass was of 40 inches and 6 lines focal di- 

 stance, and 30 lines and a half of aperture;— this telescope has an 

 eye-glass of 2 inches focal distance, and is of admirable clearness. 

 It is^mounted on a parallactic foot, but required the appropriation 

 of a micrometer, before it could be well applied to this class of ob- 

 servations. On the 4th, 5th and 6th of April, he made some good 

 observations on the comet with this apparatus : on the 7th he could 

 not find it, nor has he seen it since. He had no suspicion that this 

 was any other comet than the one observed by M. Gambart. until 

 he compared his own observations with those recorded in No. 4, 

 vol. xiv. of Zach's Correspondance Astronomique, from which he at 

 once saw that his observations and M. Gambart's related to two 

 different phenomena. M. Flaugergues has communicated his ob- 

 servations on the evenings of the 4th, 5th, and 6th of April; and 

 though they are nearer together than could be wished, he has de- 

 duced from the corresponding geocentric places, the following ele- 

 ments of the orbit, regarded as parabohc : 



Inclination 9° 32' 26" 



Longitude of the ascending node 193 31 11 



Longitude of perihelion 222 53 32 



Perihelion distance 0-646146 



Passage of perihelion, April, 2695973 ; or 



26th of April, 23" 2™ 0^ M.T. at Viviers. 

 Motion direct. 

 It is only in this last element, that this comet resembles the 

 comet announced by M. Gambart. 



There was next read a letter from M. Gambart to the Foreign 

 Secretary, dated Marseilles, 29lh of October 1826, announcing his 

 discovery, the preceding evening, of a Comet having then 14" SS^iR, 

 and 36°- 1 of Dec. North. 



From a subsequent communication to different astronomers, dated 

 Marseilles 22d of November, which was also read, it appears that 

 M. Gambart from observations of the 7th, 8th, 9th, and 10th of 

 November, computed the elements of the orbit, and thence deduced 

 a curious anticipatory result. He gives for 



Passage of the perihelion Nov. 18-80^5 M.T. from midn*. 



Perihelion distance 0-02314 



Longitude of perihelion .... 314° 57' 28" 

 Longitude of the ascending node 236 9 54 



Inclination 89 59 24 



Motion retrograde. 

 From these elements, it was anticipated that the comet would 

 transit the sun's disc on the 18th of November, and that 



The Immersion would take place at 5" 25°" A.M. 



Passage through the node 7 1 



Shortest distance of comet from ©"s centre 2' 40" 



Emersion of comet from disc 8 38 



The expected phaenomenon was not observed in England. 



There 



