Il6 ON COMETS. 



ever, never seemed to be able to get far out towards the 

 sun, but always to be driven back and forced into the 

 tail, as if by the action of a violent wind setting against 

 them, always from the sun, so as to make it clear that 

 this tail is neither more nor less than the accumulation 

 of this sort of luminous vapour darted off in the first 

 instance TOWARDS the sun, as if it were something raised 

 up, and, as it were, exploded by the sun's heat, out of 

 the kernel, and then immediately and forcibly turned 

 back and repelled from the sun. 



(28.) As this comet approached the sun, its tail, far 

 from increasing, diminished ; and between the middle of 

 November and the 2ist of January, strange to say, both 

 head (that is coma) and tail were altogether destroyed, 

 or at least rendered invisible. On the 2 ist of January 

 the comet was actually seen like a small star without any 

 tail or any haziness, and was only known not to be a star 

 by being exactly in its calculated place, and by its not 

 being there next night. After that its head seemed to 

 form again round this star, and grew rapidly and visibly 

 from night to night, putting on appearances which could 

 not be clearly apprehended without elaborate figures. 

 This growth of the comet was so very rapid, that in the 

 interval of 17 days from the time I first saw it as a round 

 body its real bulk had increased to 74 times the size .it 

 then had and at the same rate it continued to swell 

 out, not, however, preserving a round form, but growing 

 longer in proportion to its breadth as if it intended to 

 develop a new tail. But this it never did the dilatation 

 or swelling out continued, and at one time it had exactly 



