398 COMETS. 



DE LA HIRE, and other astronomers, are of 

 opinion, that Comets never return. CASSINI, 

 and others, think it probable that they do ; 

 but NEWTON, HALLEY, FLAMSTEAD, and the 

 generality of the English astronomers, bigotted 

 and rivetted to their own system, are per- 

 suaded that they have their regular periods, 

 although they are not so well ascertained, as 

 those of the planets. De la Hire, and Cassini, 

 observed a Comet in 1698, which they sup- 

 posed, from the velocity of the motion, and the 

 path which it described, to be the same as was 

 seen in 1 652 ; its period appeared to have been 

 43 months ; and the number of revolutions from 

 1652, to 1698, they supposed to have been 14. 

 It is, however, very justly observed, that in an 

 age wherein the heavens are so narrowly 

 watched, it is hard to beHeve, that a Comet 

 such as this, should make, unperceived, 14 

 revolutions ; more especially as a Comet of that 

 description, might appear visible above a 

 month together. The Comet of 1702, viewed 

 by Cassini, and which he concluded to have 

 been the one seen in 1668, giving it a period of 

 36 years, has never again appeared, more than 

 a variety of others that might be mentioned. 

 Dr. Halley suspected that the Comet observed 

 by Apian, in 1532, was the same Comet as 

 had been observed by Hevelius, in 1661 : if 



