THE RENAISSANCE 117 



science is not only born, but has come to an age of 

 steady work. Moreover, he collected and published 

 his researches, and thus gave them at once to the world. 



As an astronomer, Galileo's fame rests on his applica- 

 tion of the telescope and the confirmatory evidence 

 he thus gave to the Copernican system. It was the 

 expression of his conclusions from these researches, 

 embodied in a volume of which the dedication was 

 originally accepted by the Pope, that brought Galileo, 

 when his book had been read and understood, within 

 reach of the Inquisition, and forced him to recant his 

 heresies. 



But Galileo's chief and most permanent work was 

 the foundation of the modern experimental and mathe- 

 matical science of mechanics. In this he showed 

 himself a true master of method. 



Before Galileo, in spite of Leonardo's superhuman 

 insight, most men's ideas of mechanics were a con- 

 fused medley of Aristotelian dogmas. Bodies were 

 thought to be intrinsically heavy or light and to fall 

 or rise with varying velocity because they " sought 

 their natural place " with varying power. Galileo set 

 himself to discover not why, but how, things fell. In 

 itself this attitude of mind marks a great achievement. 



A body falling towards the ground moves with con- 

 stantly increasing speed. What is the law of the 

 increase ? Galileo's first hypothesis, quite reasonable 

 in itself, was that the speed was proportional to the 

 distance fallen through. But Galileo soon showed 

 that this supposition involved a contradiction, and 

 tried another, namely that the speed increased with 

 the time of fall. This hypothesis was found to involve 

 no obvious difficulty, and Galileo proceeded to deduce 



