GALILEO AND THE OPTIC TUBE 207 



But the talons of the Inquisition could not hold their prisoner 

 long. At seventy-eight he passed beyond their reach. He 

 passed in poverty, in blindness and disgrace the greatest 

 intellectual glory of Florence and modern Italy. At Arcetri, 

 a little hamlet in the hills back of the Tuscan capital, they 

 show you the wretched hovel where he died, a prisoner of the 

 bloodhounds of the Church. 



It was his discovery and enlargement of the powers of the 

 telescope, and the things that he saw thereby doubtless also 

 the tragic ending of his brilliant life that gave to Galileo his 

 wide renown. But by far the most important of all his varied 

 contributions to the intellectual wealth of his kind was his 

 treatise founding the science of mechanics. While Kepler was 

 establishing the laws which govern the motion of the planets, 

 Galileo was penetrating the laws which govern the motion of 

 bodies on the earth. 



Now, here is a singular thing not singular, perhaps, if looked 

 at aright, for it is a familiarly recurring fact throughout all the 

 intellectual development of the race, but puzzling none the less. 

 Kepler in Germany, as we have seen, was haunted with his 

 endeavours to explain the cause of planetary motion ; he had 

 likened the sun, as we have seen, to a vast magnet, and tries 

 to find out if its force weakens directly with the distance or 

 with the square of the distance. He can find no facts, no 

 data, which will give him a clue. Yet Galileo had mined out 

 the material for him and put it in a little Latin treatise on 

 mechanics, written in 1592. Their friendship began early, and 

 ended only with Kepler's death. They exchanged many letters, 

 exchanged ideas, exchanged books. 



But Kepler, so quick to grasp the ideas of Coppernicus and 

 carry them still further, so proud of Galileo's discoveries in 

 the heavens, hailing them with delight even when they over- 

 turn some of his most cherished notions, yet cannot link with 

 his own thought, nor see the bearing of Galileo's measures of 

 motion and his mechanical laws. These would have given him 

 just the material he sought ; could he have grasped the import 

 of his friend's far more important discoveries in mechanics, he 

 would have completely anticipated Newton, as he came so 

 wonderfully near to doing. But no, he cannot see. 



You marvel, but it is the same with Galileo. What, so far 

 as we know, no other man who had ever lived had thought of 



