86 Mr Dunlop's observations on the Comet of 1 825. 



the case, but that it was the instant of the small nucleus pas- 

 sing over the star. 4 



Oct. 4>th. — At 1 2 h 0' mean time, the tail of the comet is 10° 

 or 11° long, and about 2£° broad. The nucleus of the comet 

 is sensibly nearer the preceding side of the head, and not in the 

 centre, as I have formerly observed it. 



Oct. 5th. — At 9 h 30' mean time, the comet is north following 

 417 Cetus, about one minute of R.A. in time, and about 20 x north 

 of the star ; the tail is about 10° in length, and perhaps 2° broad 

 at the extremity. The tail is brightest in the middle and conti- 

 nues for about 3° or 4° from the head, without very sensibly 

 varying in breadth. It passes north following of g Ceti, where 

 it begins suddenly to increase in breadth, and the 363 Ceti is 

 involved near the preceding side of the tail, where the faintness 

 commences ; but nearly in the direction of s Ceti, there is the ap- 

 pearance of a second branch forming, which at present is not more 

 than one fourth of a degree in length. (See Plate II. Fig. 1.) 



Oct. 7th. — At 11 h mean time, the tail of the comet is about 9° 

 in length, and very faint towards the extremity, and is divided 

 into five bars or branches, with a dark space between each. 

 The principal branch is rather preceding the central line of the 

 tail, and is considerably the longest and brightest ; the branch 

 on the following side is longer than that on the preceding side; 

 as about 7° to 3° from the head to where the branches separate 

 is about one degree. The light of this space in the neck is 

 nearly uniform, but not equal in brightness to the head. The 

 head seems much more condensed than it was on Wednesday, 

 (the 5th) and much brighter, but the tail, as a whole, is fainter 

 and shorter. (See Fig. 2.) 



N. B. — The tail is nearly due north, probably rather pre- 

 ceding. 



Oct. 9th. — At 12 h mean time, the tail of the comet is north 

 preceding. The branches do not exist, neither does the tail 

 spread so much at the extremity ; as on the 7th, it is pretty 

 bright for about two degrees from the head, then breaks off 

 faint, suddenly. 



Oct. 10//*.— At 11" 37' mean time, the tail is fully 1 1° or 12* 

 in length, diverging very suddenly for about 2 \° from the head ; 

 the following side of the head is not so well-defined as the pre- 



11 



