THE GEOLOGY OF THE BOTTOM OF THE SEAS. 
By L. pe Launay, 
Membre de V Institut, Professeur 4 V Ecole supérieure des Mines. 
Notwithstanding so many important discoveries, the oldest of which 
date back scarcely more than a century and a half, geology, a very 
young science, is still full of mystery. We are laboriously trying to 
reconstruct a story which had no human witnesses, the traces of 
which have been for the greater part destroyed or are to-day buried 
under the mountains or the seas at depths compared with which 
the thickness of the ash which covers Pompeii seems trivial. Little 
by little we bring together again some scattered shreds; we compare 
them with present phenomena which seem to us to offer an analogy, 
and proceeding by inference we try to reach some general conclusions 
which by later investigation we may verify experimentally in certain 
details. But at least we must have the testimony as full as possible 
of all these existing traces of ancient phenomena or of present com- 
parable phenomena. All that the geologist can do is to go over the 
surface of the globe, hammer in hand, observing and collecting as 
he goes. As a rule, he does not dig; he personally does not search 
below the surface, for the means, except in some favored countries, 
would be lacking for that work. THe is therefore compelled to plead, 
to beg for aid in every quarter. He asks it chiefly from miners, from 
well diggers, from builders of tunnels and from excavators who pene- 
trate beneath the soil for him. He seeks it from explorers, who, 
though inexperienced in geology, visit the less accessible regions of 
the globe, the deserts, the polar glaciers. He will demand it even 
from astronomers who bring him cosmic elements for comparison and 
to whom he will try in exchange to furnish, for the interpretation of 
a vast universe, positive evidences and precise facts established on 
our little earth. He will demand much—and this is the point which 
I wish to examine—from oceanographers whose bold explorations 
have for their aim to in some degree increase our knowledge of what 
we here term the geology of the bottom of the seas. 
Oceanography i is the geology of the future just as physical eeog- 
raphy is in certain respects the geology of the present and as geology 
proper is, above all, the reconstruction of the past. 
1 Stenographic report ofalecture before the Institut Oceanographique de Paris, November 22, 1913. 
Translated by permission from Revue Scientifique, Paris, Jan. 3, 1914. 
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