344 PR A GMENTS OP SCIENCE. 



failh in the priest's blessing; still, he deemed his prayer 

 different in kind from a request to open a new river-cut, 

 or to cause the water to flow uphill. 



In a similar manner the same Protestant gentleman 

 would doubtless smile at the honest Tyrolese priest, who, 

 when he feared the bursting of a glacier dam, offered the 

 sacrifice of the Mass upon the ice as a means of averting 

 the calamity. That poor man did not expect to convert 

 the ice into adamant, or to strengthen its texture, so as to 

 enable it to withstand the pressure of the water; nor did 

 he expect that his sacrifice would cause the stream to roll 

 back upon its source and relieve him, by a miracle, of its 

 presence. But beyond the boundaries of his knowledge 

 lay a region where rain was generated, he knew not how. 

 He was not so presumptuous as to expect a miracle, but he 

 firmly believed that in yonder cloud-land matters could be 

 so arranged, without trespass on the miraculous, that the 

 stream which threatened him and his people should be 

 caused to shrink within its proper bounds. 



Both these priests fashioned that which they did not 

 understand to their respective wants and wishes. In their 

 case imagination came into play, uncontrolled by a knowl- 

 edge of law. A similar state of mind was long prevalent 

 among mechanicians. Many of these, among whom were 

 to be reckoned men of consummate skill, were occupied a 

 century ago with the question of perpetual motion. They 

 aimed at constructing a machine which should execute 

 work without the expenditure of power, and some of them 

 went mad in the pursuit of this object. The faith in such 

 a consummation, involving, as it did, immense personal 

 profit to the inventor, was extremely exciting, and every 

 attempt to destroy this faith was met by bitter resentment 

 on the part of those who held it. Gradually, however, as 

 men became more and more acquainted with the true 

 functions of machinery, the dream dissolved. The hope 

 of getting work out of mere mechanical combinations dis- 

 appeared: but still there remained for the speculator a 

 cloud-land denser than that which filled the imagination 

 of the Tyrolese priest, and out of which he still hoped to 

 evolve perpetual motion. There was the mystic store of 

 cheinic force, which nobody understood; there were heat 

 and light, electricity and magnetism, all competent to pro- 

 duce mechanical motion.* Here, then, was the mine in 



* See Helmlioltz: " Wechselwirkung der Naturkrafte." 



