194 
THE FAIRY-LAND OF SCIENCE. 
up for days fully two hundred feet above the surface 
of the earth, forming, as it flowed toward the sea, rivers 
of oil many miles in length. The force of coal-gas es- 
caping from the coal-gas wells in Indiana, Pennsyl- 
vania, and Ohio, has been known to blow out drills of 
nearly a ton in weight, and to burst the doubly-riveted 
tanks and heavy iron mains which were used in at- 
tempting to confine it, so that it was for a time thought 
that nothing could be contrived that would withstand 
its pressure. The roar of the escaping gas could be 
heard for miles, and schools had to be closed and 
all business suspended in the vicinity of the wells. 
If the gas was set on fire, as sometimes happened, 
the roaring was increased to such an extent that 
workmen who were obliged to remain in its neigh- 
bourhood were made deaf for life, and the light from 
the well could in some cases be seen for forty miles 
around. 
Until the last few years, however, the very exist- 
ence of most of these great reservoirs of potential en- 
ergy was unsuspected, and although coal-oil skimmed 
from the surface of pools in oil-bearing localities was 
sometimes employed to a limited extent, mostly as a 
medicine, it is only of late years it has been found in 
quantities sufficient to allow its extended use. Yet so 
rapid has its applications to uncounted domestic, me- 
chanical, and industrial purposes advanced that it may 
already justly claim to materially modify our progress 
in the arts and sciences. 
Not only is mineral oil now used to cook our 
food, to light our houses, and to drive our engines, but 
the manufacture of a great number of articles and of 
