COMETS. 



disappearance, have been described with great clearness by Mr. 

 Maclear, and illustrated by a beautiful series of drawings by that 

 astronomer and his assistant, Mr. Smith, in a memoir which 

 appeared in the tenth volume of the Transactions of the Royal 

 Astronomical Society, from which we reproduce the series of 

 illustrations given in figT 19 to fig. 29. 



101. On the night of the 24th of January, 1836, the comet 

 appeared, as in fig. 19, visible to the naked eye as a star of the 

 second magnitude. The head was nearly circular, and presented 

 a pretty well-defined planetary disc, encompassed by a coma or 

 halo of delicate gossamer-like brightness. The diameter of the 

 head, without the halo or coma, measured 131", and with the 

 latter 492". 



102. On the night of the 25th the comet had the appearance 

 represented in fig. 20. The circular form was broken, and the 

 magnitude of the head was increased. Three stars were seen 

 through the coma and one through the head. 



103. On the 26th of January the magnitude of the head was- 

 further increased, but that of the coma was diminished (fig. 21). 



104. On the 27th the comet began to assume a parabolic form, 

 as shown in fig. 22, and the increasing magnitude continued. 



105. On the 28th the coma or halo was quite invisible, but 

 the nucleus appeared like a faint small star. The magnitude of 

 the comet continued to increase. The observer fancied he saw the 

 faint outline of a tail (fig. 23). 



Fig. 23. January 28, 1836. 



106. On the 30th the form of the comet became decidedly 

 parabolic (fig. 24). The breadth across the head was 702", being 

 greater than on the 24t'i in the ratio of 49 to 70, or 7 to 10, 

 206 



