344 FRAGMENTS OF SCIENCE. 
faith 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 
chemic 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 Helmholtz: " Wecliselwirkung der Naturkrafte." 
