93 



CHAP. XV. 



Of the Revolution of the Planets about their own 

 Axis. 



1. Jut OW useful an aid the invention of telescopes 

 hath beeu to the astronomical observations of the mo- 

 dernb, is particularly evident from their discovery, that 

 the planets revolve on their axis ; a discovery founded 

 on ehe periodical revolution of the spots observed on 

 their disks : so that every planet performs two revo- 

 lutions, by the one of which it is carried with others 

 about a common centre ; and by the other moves upon 

 its axis round its own. But all (hat the moderns have 

 advanced in this respect, serves only to confirm) to the 

 ancients, tiie glory of being the first discoverers. The 

 moderns are in this to the ancients, as tne French 

 philosophers are to Sir Isaac Newton, all whose la. 

 botirs and travels in visiting the poles and i-q niiur to 

 determine trie figure of tiie, earth, serve only to con. 

 firm what Sir Isaac had Uiougntol it, without so much 

 as stirring from his closet, in the same manner, we 

 have proved, that most of our experiments have sei -red, 

 aud do stiil contribute to confirm am! support t.ie con- 

 jectures of the ancients ; although it hatu often hap* 

 pened^ that those wry conjectures of theirs, inch 

 are now so gem rally received as true, have formeily 

 been as generally dcctied. Of this we have had in- 

 stances in tiie preceding chapter, aud the present, will 

 exhibit another not less remarkable. 



2. Whatever were the arguments upon which the 



