CH. XL GALILEO. 87 



CHAPTER XL 



SCIENCE OF THE SEVENTEENTH CENTURY. 



Astronomical discoveries of Galileo The Telescope Galileo examines 

 the Moon, and discovers the Earth-light upon it Discovers Jupiter's 

 four Moons Distinguishes the Fixed Stars from the Planets The 

 phases of Venus confirm the Copernican theory Galileo notices 

 Saturn's Ring, but does not distinguish it clearly Observes the 

 spots on the Sun The Inquisition force him to deny the movement 

 of the Earth Blindness and Death of Galileo. 



Astronomical Discoveries of Galileo, 1 609-1 642. The seven- 

 teenth century was not many years old when Galileo startled 

 the world with discoveries such as had never been heard of 

 before. He relates that when quite a young man he was so 

 struck with an account given by some of his companions of 

 a lecture on the Copernican theory, that he determined to 

 study it, and he soon became convinced of its truth. Never- 

 theless he saw how difficult it would be to prove that the earth 

 moves round the sun, and not the sun round the earth. 



When he went to Padua he gave a great deal of time to 

 the study of astronomy, and had already made some 

 remarkable observations, when one day, in the year 1609, 

 being in Venice, he heard that a Dutch spectacle-maker had 

 invented an instrument which made distant things appear 

 close at hand. 



This discovery, which Bacon and Porta had foreseen, 

 was made at last almost by accident in Holland, by two 

 spectacle-makers, Zacharias Jansen and Henry Lippershey. 



