COMETS. 399 



that had been the case, it ought to have returned 

 in 1789, or 1790, which it never did. 



From the earliest periods, a variety of Comets 

 have appeared, that were neither anticipated 

 nor expected ; and whose motions and ap- 

 pearances have born neither analogy nor resem- 

 blance to the history which has been given of 

 those of former times. The history of the Co- 

 met described by Hevelius, in 1661, perhaps, 

 conveys the most precise idea of the change 

 which it is presumed Comets undergo. Its 

 body was of a yellowish color, very bright and 

 conspicuous, but without any glittering light ; 

 in the middle was a dense, ruddy nucleus, al- 

 most equal in size to Jupiter, encompassed with 

 a much fainter, thin matter : Feb. 5, its head 

 was somewhat bigger, but its light more dusky, 

 than the rest of the stars ; here the nucleus 

 appeared divided into several parts. Feb. 6, 

 the disk lessened, the nuclei still existed, though 

 less than before ; one of them on the lower part 

 of the disk, much denser and brighter than the 

 rest ; its body round, and representing a very 

 lucid little star ; the nuclei still encompassed 

 with another kind of matter. Feb. 10, the 

 head somewhat more obscure, the nuclei more 

 confined, but brighter at top than at bottom. 

 Feb. 13, its head diminished, both in magni- 

 tude and brightness. March 2, its roundness 

 a little impaired, its edges lacerated. March 



