ASTRONOMY 177 



relative movements and the infinite magnitude of the 

 universe ; 



2. By the hypothesis of Kepler regarding the 

 elliptic movement of the planets, a brilliant hypothesis, 

 since it led to a very great simplification in the calcula- 

 tions, without being contrary to the appearances ; 



3. By the researches of Galileo on weight, and by his 

 observations on sun-spots ; for the results thus obtained 

 finally demolished the physical theories of Aristotle 

 concerning loci and the opposition between the celestial 

 and sublunar regions. 



It was therefore owing to the works of Kepler and 

 Galileo that the mathematical and physical hypotheses 

 could harmoniously blend and that astronomy could 

 enter upon new paths. 



