THE LAWS OF GEOLOGICAL ACTION. 9 
very remote, it is true, and perhaps unrecorded in the history 
of the earth—in which the known physical forces may have 
acted with an intensity much greater than direct observation 
would lead us to imagine. And this may be believed, alto- 
gether irrespective of those great secular changes by which hct 
or cold epochs are produced, and which can hardly be called 
“catastrophistic,” as they are produced gradually, and are 
lable to recur at definite intervals. 
Admitting, then, that there zs a truth at the bottom of the 
once current doctrines of catastrophism, still it remains certain 
that the history of the earth has been one of /azw in all past 
time, as itis now. Nor need we shrink back affrighted at the 
vastness of the conception—the vaster for its very vagueness 
—that we are thus compelled to form as to the duration of 
geological time. As we grope our way backward through the 
dark labyrinth of the ages, epoch succeeds to epoch, and 
period to period, each looming more gigantic in its outlines 
and more shadowy in its features, as it rises, dimly revealed, 
from the mist and vapour of an older and ever-older past. It 
is useless to add century to century or millennium to millen- 
nium. When we pass a certain boundary-line, which, after all, 
is reached very soon, figures cease to convey to our finite 
faculties any real notion of the periods with which we have 
to deal. The astronomer can employ material illustrations 
to give form and substance to our conceptions of celestial 
space; but such a resource is unavailable to the geologist. 
The few thousand years of which we have historical evidence 
sink into absolute insignificance beside the unnumbered eons 
which unroll themselves one by one as we penetrate the dim 
recesses of the past, and decipher with feeble vision the pon- 
derous volumes in which the record of the earth is written. 
Vainly does the strained intellect seek to overtake an ever- 
receding commencement, and toil to gain some adequate grasp 
of an apparently endless succession. A beginning there must 
have been, though we can never hope to fix its point. Even 
speculation droops her wings in the attenuated atmosphere of 
a past so remote, and the light of imagination is quenched in 
the darkness of a history so ancient. In “me, as in space, the 
confines of the universe must ever remain concealed from us ; 
and of the end we know no more than of the beginning. In- 
conceivable as is to us the lapse of “ geological time,” it is no 
more than ‘“‘a mere moment of the past, a mere infinitesimal 
portion of eternity.” Well may “the human heart, that weeps 
and trembles,” say, with Richter’s pilgrim through celestial 
space, ‘‘I will go no farther; for the spirit of man acheth with 
