CH. XI. 



GALILEO. 85 



CHAPTER XI 



SCIENCE OF THE SEVENTEENTH CENTURY. 



Astronomical Discoveries of Galileo The Inquisition force him to 

 deny the Movement of the Earth Blindness and Death. 



Astronomical Discoveries of Galileo, 1609-1642. 



The seventeenth 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 con- 

 vinced of its truth. Nevertheless, 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. 

 It is related that Jansen's children, when playing one day 

 with two powerful magnifying glasses, happened to place 



