522 



Royal Astronomical Society. 



IX. The following Communications respecting the great Comet 

 of 1843*:— 



1. Observations of the Comet, made by J. Burdwood, Esq., 

 Master of H. M. Sloop Persian. Communicated by G. B. Airy, Esq. 



The comet was seen very distinctly for several successive evenings 

 in March, while the vessel was cruising off the western coast of 

 Africa, between 0° 40' east, and 0° 13' west longitude; and be- 

 tween 5° 10' and 5° 30' north latitude. The following distances 

 were observed with the sextant on the evening of March 7, at 

 7 h 10 m p.m. :— 



Distance from Alclebaran 60 29 



Canopus 75 57 



Sirius 84 



Length of tail 27 25 



2. Remarks on the Comet, as seen on Board the Lawrence, of 

 Liverpool, on her passage from Sidney to Conception. By a Pas- 

 senger. Communicated by W. Simms, Esq. 



The comet was first seen on the 1st of March, at 8^ p.m., as a 

 white streak of light, inclined at an angle of 40° to the horizon, and 

 was imagined to be the zodiacal light. It was again seen on the 6th, 

 when the tail was 50° in length, in two streams of light, the outside 

 edges being clear and well-defined. On the 9th, the nucleus was 

 seen, and appeared as bright as stars of the third or fourth magni- 

 tude. It was seen at intervals till the 28th of March. 



3. Abstract of an article in Silliman's Journal, containing au Ac- 

 count of Observations of the great Comet, made near the time of its 

 Perihelion Passage. By J. G. Clarke, Esq., of Portland. 



Mr. Clarke measured the distance of the nucleus from the sun on 

 the 28th of February, and states, that the nucleus and every part of 

 the tail, as seen by him in strong sunshine, were as well defined as 

 the moon on a clear day, and resembled a perfectly pure white cloud, 

 without any variation, except a slight change near the head, just 

 sufficient to distinguish the nucleus from the tail at that point. The 

 denseness of the nucleus was so great that Mr. Clarke has no doubt 

 that it might have been visible upon the sun's disc, if it had passed 

 between it and the observer. This apparent density he attributes to 

 the foreshortening of the tail, and its being so directed to the earth 

 that the nucleus must have been seen through a considerable mass 



* Preceding communications respecting this comet have appeared in 

 the present volume, p. 300. 



