ocean depths, and in the piled strata of the globe. We untrained
observers cannot spell out these texts, because they are written
large; our vision is adjusted to smaller print; we are like the
school-boy who finds on the map the name of a town or a river, but
does not see the name of the state or the continent printed across
it. If the geologist did not tell us, how should we ever suspect
that probably where we now stand two or more miles of strata have
been worn away by the winds and rains; that the soil of our garden,
our farm, represents the ashes of mountains burned up in the slow
fires of the geologic ages.

Geology first gives us an adequate conception of time. The
limitations which shut our fathers into the narrow close of six
thousand years are taken down by this great science and we are
turned out into the open of unnumbered millions of years. Upon the
background of geologic time our chronological time shows no more
than a speck upon the sky. The whole of human history is but a mere
fraction of a degree of this mighty arc. The Christian era would
make but a few seconds of the vast cycle of the earth's history.
Geologic time! The words seem to ring down through the rocky strata
of the earth's crust; they reverberate under the mountains, and make
them rise and fall like the waves of the sea; they open up vistas
through which we behold the continents and the oceans changing
places, and the climates of the globe shifting like clouds in the
sky; whole races and tribes of animal forms disappear and new ones
come upon the scene. Such a past! the imagination can barely skirt
the edge of it. As the pool in the field is to the sea that wraps
the earth, so is the time of our histories to the cycle of ages in
which the geologist reckons the events of the earth's history.