he majority of eighteenth-century philosophers in
their attempts to study what we now term geology. Deluded by the old
deductive methods, they founded not a science, but the ghost of a
science, as immaterial and as unlike anything in nature as any other
phantom that could be conjured from the depths of the speculative
imagination. And all the while the beckoning earth lay beneath the feet
of these visionaries; but their eyes were fixed in air.

At last, however, there came a man who had the penetration to see that
the phantom science of geology needed before all else a body corporeal,
and who took to himself the task of supplying it. This was Dr.
James Hutton, of Edinburgh, physician, farmer, and manufacturing
chemist--patient, enthusiastic, level-headed devotee of science.
Inspired by his love of chemistry to study the character of rocks and
soils, Hutton had not gone far before the earth stood revealed to him
in a new light. He saw, what generations of predecessors had blindly
refused to see, that the face of nature everywhere, instead of being
rigid and immutable, is perennially plastic, and year by year is
undergoing metamorphic changes. The solidest rocks are day by day
disintegrated slowly, but none the less surely, by wind and rain and
frost, by mechanical attrition and chemical decomposition, to form the
pulverized earth and clay. This soil is being swept away by perennial
showers, and carried off to the oceans. The oceans themselves beat on
their shores, and eat insidiously into the structure of sands and rocks.
Everywhere, slowly but surely, the surface of the land is being worn
away; its substance is being carried to burial in the seas.

Should this denudation continue long enough, thinks Hutton, the entire
surface of the continents must be worn away. Should it be continued LONG
ENOUGH! And with that thought there flashes on his mind an inspiring
conception--the idea that solar time is long, indefinitely long. That
seems a simple enough thought--almost a truism--to the twentieth-century
mind; but it required genius to conceive it in the eighteenth. Hutton
pondered it, grasped its full import, and made it the basis of his
hypothesis, his "theory of the earth."

MODERN GEOLOGY

The hypothesis is this--that the observed changes of the surface of
the earth, continued through indefinite lapses of time, must result in
conveying all the land at last to the sea; in wearing continents away
till the oceans overfl