Mr Dunlop's observations on the Comet of 1825. 87 



ceding side, and the nucleus is not in the centre of the head, 

 but certainly in the preceding side of it, which side is sharply 

 defined. The broadest part of the tail is little more than one 

 degree, and the position of the tail north rather preceding. 



At 12 h 17 / mean time, the tail very gradually diminishes in 

 brightness from the head to the faint extremity, which may be 

 about 1 1° in length, and one degree broad ; the narrowest part of 

 the tail is not immediately joining the head, but about one degree 

 distant, where it diverges rather suddenly to about 2J° from 

 the head, and remains nearly of the same breadth to the faint 

 extremity ; the tail is north preceding. (See Fig. 3.) 



Oct. Iflth. — At ll h 21' mean time, the tail of the comet is 

 singularly curved concave towards the east, or following side, 

 and fully 7° in length ; there is a considerable branch on 

 the preceding side, about three degrees in length, and also a 

 short branch about one degree in length on the following side ; 

 the head is much condensed, more so indeed, than ever I have 

 seen it ; the tail is about 7° or 8° long, and somewhat less than 

 2° broad. (See Fig. 4.) 



At 13 h 27' mean time, the tail is certainly more suddenly 

 curved close to the head, and the principal branch is divided 

 into two ; the preceding branch is brighter, and considerably in- 

 creased in length ; and the following short branch is more filled 

 up towards the principal branch ; the tail seems rather broader, 

 and is certainly shorter than it was at ll h 21'. 



At 14 h 17', the general appearance much the same as at 

 12 h 27' ; the tail is about 3° broad at the extremity of the branch- 

 es, and not more than 7° in length, the tail is evidently much 

 broader than it was at ll h 21', and shorter ; but the branch on 

 the following side has increased considerably in length. (See 

 Fig. 5.) 



Oct. 14ith. — At 8 h 10' mean time, the tail of the comet is 

 certainly much longer than it was on the 12th, and very differ- 

 ent in appearance ; it is fully 10° in length. The head is less 

 bright, and the nucleus or (condensed part) is neither so bright, 

 nor so large. The preceding side of the tail is strongly marked, 

 bright, and well-defined for about 3£° from the head, where a 

 faint narrow branch strikes off at a considerable angle, and 

 nearly equal in length with the principal branch ; also a very 

 considerable nebulosity exists on the following side, shooting 



