GALILEO 



instruments, with an essay showing what important 

 consequences must result therefrom in navigation and 

 astronomy. This was the invention of the telescope. 

 The imperfect arrangement of lenses made by Lipper- 

 shey, of which Galileo had heard, and which started 

 him on his own experiments, was at the best only a 

 spy-glass or field-glass, and was fitted only for such 

 limited uses. Galileo was rewarded by the appoint- 

 ment for life to the professorship, with a salary three 

 times as great as he had before received. Galileo 

 soon after invented the microscope, and perfected the 

 telescope so that it might be turned towards the sky. 

 " He then saw what no mortal had seen before him 

 the surface of the moon, like a land furrowed by 

 mountains and deep valleys; the planet Venus pre- 

 senting itself in phases that proved it to be a sphere ; 

 Jupiter accompanied by the four satellites that sur- 

 rounded it in its course through the heavens. The 

 milky way resolved into an infinitude of stars that 

 were too small to be seen by the naked eye. He 

 noticed also the various shapes presented by the 

 planet Saturn, but did not resolve the changes into 

 the presence of its ring. He distinguished the spots 

 on the sun, which the peripaticians had declared to be 

 without blemish and incorruptible. From them he de- 

 duced the fact of the rotation of the sun on its axis."* 



* Biot. Biog. Univs. T. 15, P. 413. 

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