Time and Life | Page 4

were infinitely more intense than now, and
hence the time through which they acted to produce the effects we see
was comparatively short.
The earlier geologists adopted the latter view almost with one consent.
For they had little knowledge of the present workings of nature, and
they read the records of geologic time as a child reads the history of
Rome or Greece, and fancies that antiquity was grand, heroic, and

unlike the present because it is unlike his little experience of the
present.
Even so the earlier observers were moved with wonder at the seeming
contrast between the ancient and the present order of nature. The
elemental forces seemed to have been grander and more energetic in
primeval times. Upheaved and contorted, rifted and fissured, pierced by
dykes of molten matter or worn away over vast areas by aqueous action,
the older rocks appeared to bear witness to a state of things far different
from that exhibited by the peaceful epoch on which the lot of man has
fallen.
But by degrees thoughtful students of geology have been led to
perceive that the earliest efforts of nature have been by no means the
grandest. Alps and Andes are children of yesterday when compared
with Snowdon and the Cumberland hills; and the so-called glacial
epoch--that in which perhaps the most extensive physical changes of
which any record remaining occurred--is the last and the newest of the
revolutions of the globe. And in proportion as physical
geography--which is the geology of our own epoch--has grown into a
science, and the present order of nature has been ransacked to find what,
'hibernice', we may call precedents for the phenomena of the past, so
the apparent necessity of supposing the past to be widely different from
the present has diminished.
The transporting power of the greatest deluge which can be imagined
sinks into insignificance beside that of the slowly floating, slowly
melting iceberg, or the glacier creeping along at its snail's pace of a
yard a day. The study of the deltas of the Nile, the Ganges, and the
Mississippi has taught us how slow is the wearing action of water, how
vast its effects when time is allowed for its operation. The reefs of the
Pacific, the deep-sea soundings of the Atlantic, show that it is to the
slow-growing coral and to the imperceptible animalcule, which lives its
brief space and then adds its tiny shell to the muddy cairn left by its
brethren and ancestors, that we must look as the agents in the formation
of limestone and chalk, and not to hypothetical oceans saturated with
calcareous salts and suddenly depositing them.
And while the inquirer has thus learnt that existing forces--'give them
time'--are competent to produce all the physical phenomena we meet
with in the rocks, so, on the other side, the study of the marks left in the

ancient strata by past physical actions shows that these were similar to
those which now obtain. Ancient beaches are met with whose pebbles
are like those found on modern shores; the hardened sea-sands of the
oldest epochs show ripple-marks, such as may now be found on every
sandy coast; nay, more, the pits left by ancient rain-drops prove that
even in the very earliest ages, the "bow in the clouds" must have
adorned the palaeozoic firmament. So that if we could reverse the
legend of the Seven Sleepers,--if we could sleep back through the past,
and awake a million ages before our own epoch, in the midst of the
earliest geologic times,--there is no reason to believe that sea, or sky, or
the aspect of the land would warn us of the marvellous retrospection.
Such are the beliefs which modern physical geologists hold, or, at any
rate, tend towards holding. But, in so doing, it is obvious that they by
no means prejudge the question, as to what the physical condition of
the globe may have been before our chapters of its history begin, in
what may be called (with that licence which is implied in the
often-used term "prehistoric epoch") "pre-geologic time." The views
indicated, in fact, are not only quite consistent with the hypothesis, that,
in the still earlier period referred to, the condition of our world was
very different; but they may be held by some to necessitate that
hypothesis. The physical philosopher who is accurately acquainted with
the velocity of a cannon-ball, and the precise character of the line
which it traverses for a yard of its course, is necessitated by what he
knows of the laws of nature to conclude that it came from a certain spot,
whence it was impelled by a certain force, and that it has followed a
certain trajectory. In like manner, the student of physical geology, who
fully believes in the uniformity of