204 THE WORLD MACHINE 



obscure or even undivined, the human mind finds a comforting 

 sense that it is upon solid ground. 



The knowledge of the system of satellites which circle about 

 Jupiter offered yet stronger support. This little world about 

 the great planet, says Humboldt, " presented to the intellectual 

 contemplation of men a perfect image of the larger planetary 

 and solar systems." It was soon recognised that these satel- 

 lites, or planets of a secondary order, obeyed the laws discovered 

 by Kepler. The squares of the times of their revolution were 

 as the cubes of the mean distances of the satellites from the 

 primary planet. The mere discovery of the existence of these 

 satellites threw the whole old-time conceptions into confusion. 

 The establishment of the fact that they followed the general 

 laws of planetary motion brought in anew the element of pre- 

 dictability, of consequence, and completed the rout. 



These were among the services which Galileo and his glazed 

 tube rendered to the intellectual advance of the world. There 

 was yet another which seemed to still more profoundly influence 

 the mind of the time. This was Galileo's discovery of the sun- 

 spots, and through these the sun's rotation. The human kind 

 had not yet left off all relics of the primitive sun-worship. The 

 disclosure which the telescope had brought that the face of 

 the moon was crossed and scarred with mountains and valleys, 

 had sorely troubled the Aristotelian dogma of the perfection of 

 the planets ; the spots upon the face of the sun was the finishing 

 stroke. 



The triumph of the telescope and its creator was now 

 complete. Kepler could write proudly to his friend : Vicisti, 

 Galileo / He had won. The Florentine court had brought him 

 back in honour to his native Tuscany. There was no more 

 celebrated man now in all the earth. Perhaps he gloated a 

 little in his strength. The rapier of his wit made enemies ; 

 they gathered for his undoing. The Church began to awaken 

 to its peril. The Mosaic cosmogony was being sundered and 

 riven by the hands of its friends. It is to be remembered that 

 Galileo, nominally, at least, was, like Coppernicus, a good 

 Catholic ; and so he remained to the end. 



In Florence was a zealous priest whose enmity he had 

 incurred. Soon came mutterings from Rome. Thither Galileo 

 was called. Never did his powers of dialectic shine more. He 

 writes back that he is winning all along the line ; but he reckons 



