THE PATH OF EVOLUTION 



From the pale disk of the moon that becomes 

 visible when the new or the old moon is seen, he 

 rightly concluded that the effect was caused by the 

 reflection from the earth of the sunlight thereon, it 

 being analogous to the moonlight on the earth. He 

 saw how the movements and the eclipses of the 

 satellites of Jupiter would serve a useful purpose in 

 determining longitudes, and commenced a long series 

 of observations of the planets for the construction of 

 tables for the assistance of navigators. It is with 

 justice that he is considered the real inventor of the 

 telescope as an astronomical instrument. 



Galileo was fully aware of the effect his discoveries 

 would have in establishing the truth of the Coper- 

 nican system of Astronomy and in overthrowing that 

 of the Ptolemaic and of the Aristotelian philosophy. 

 He believed himself at liberty to discredit the errors 

 that had now become too gross and apparent to be 

 longer tolerated. Unfortunately for him, he had ac- 

 cepted the offer of the Grand Duke of Tuscany, who 

 had appointed him Mathematician Extraordinary to 

 his Court, and had loaded him with favors. Galileo 

 therefore moved from Padua, where the power of the 

 Republic of Venfce protected him, and where he was 

 free and safe, to Florence, where he was far less so, 

 since the political exigencies of the state of Tuscany 

 made it much more amenable to the dictates of Rome. 



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