114 



Mr. Baxendell, F. R. A. S., read a paper entitled 

 " Observations of Comet I, 1861." 



Although this comet was not at any time a very conspicuous 

 object to the naked eye, yet some of the features which it 

 presented when viewed with a good telescope at the time of its 

 greatest brightness were sufficiently remarkable to render it an 

 object of peculiar interest to the astronomer; and I have 

 therefore thought that a brief account of the observations 

 made with the excellent instruments of Mr. Worthin^rton's 

 observatory might be acceptable to the members of this 

 Society. 



My first observation was made on the night of May 3rd, 

 1861. The comet was then already visible to the naked eye 

 as a dull, hazy-looking star of the 4 J magnitude. At lOh. 

 17m. 48'7s. G.M.T. a comparison with the star Arg, 

 178,8 = 190,112 made with the equatorially-mounted achro- 

 matic of 5 inches aperture, and a dark field photographed 

 micrometer constructed by Mr. Dancer, gave the comet's 

 apparent place R.A. lOh. 5m. 27*76 Dec. 4-48° 52' 7-7". 

 Turning the 13-inch reflector upon the comet with powers of 

 81 and 196, it was found that the nebulosity was more than 

 20' in diameter, considerably condensed in the middle, but 

 without any distinct planetary or stellar nucleus. There was 

 a faint tapering elongation extending about a quarter of a 

 degree from the north following side, and stars of the 11th 

 and 12th magnitude were easily seen through the comet at the 

 distance of half a radius from its centre. 



May 4th. Three comparisons with Arg. 173,122 gave the 

 place of the comet at 9h. 26m. l9-3s. G.M.T. R.A. 9h. 52m. 

 19-83S. Dec. +45° 18' 28-1". 



With the 13-inch reflector the diameter of the nebulosity 

 constituting the head of the comet, carefully estimated by 

 comparison with the known diameter of the field of view, was 

 22'. It was much condensed in the middle, but there was 

 certainly no distinct stellar nucleus. The centre of greatest 



