T. Mellard Reade— Oceans and Continents. store 
the main ocean once more to overspread the greater part of Europe.” 
To this period, termed the Jurassic, “we can trace back the origin 
of a large part of the rock now forming the surface of the continent.” 
The next long era was the Oretaceous. “ During that time the 
Atlantic sent its waters across the whole of Europe and into Asia.” 
When we turn to the succeeding geological period, that of the Eocene, 
the proofs of widespread submergence are still more striking. <A 
large part of the Old World seems to have sunk down ; for we find 
that one wide stretch of sea extended across the whole of Central 
Europe and Asia. After this, “the subterranean movements began 
to which the present configuration of Europe is mainly due.” I give 
these copious extracts, because it is the first attempt I have met with to 
draw a definite picture of the process by which a continent has been 
built up, on the assumption that the great oceans and great continents 
as they exist now are, so to speak, permanent features of the earth. 
But does this description bear out such a theory ? We have the 
Silurian, Carboniferous, Jurassic, Cretaceous and Eocene seas cover- 
ing the greater part of what is now the continent of Europe, and 
the latter the greater part of Asia as well. Where at this time was 
the land? In the “north-west:” but that is a very general 
description of its whereabouts! We have Silurian strata stretching 
from New York to the Arctic regions, and Cretaceous and Tertiary 
strata in Greenland and Spitzbergen. The more we try to follow 
this complicated geological geography, the more it eludes our grasp. 
We cannot but admit to ourselves that the materials for anything 
like accurate pictures of the outlines of the geography of the so- 
called “periods” do not exist, and though it may be a useful exercise 
of the imagination to try and draw them, few deductions of any 
permanent value can in this way be made, much less can the founda- 
tions of a theory of the earth be laid. 
Again, it is said that all the rocks we know of are shallow-water 
deposits, and have been laid down either as littoral deposits, or 
in shallow seas on the margins of land. 
With seas in the various periods covering the principal portion of 
Europe and Asia, does not that fact, if admitted, constitute a greater 
difficulty in accepting Mr. Geikie’s explanation than it does in the 
older idea of the general interchange of land and sea? 
But I for one am not prepared to admit that the rocks of the 
earth are all of littoral or shallow-water formation. Professor Alex. 
Agassiz describes dredging up from over 1060 fathoms, 15 miles 
from land, in the Gulf of Mexico,! masses ,of leaves, pieces of 
bamboo, of sugar cane, dead land shells and other land debris, which 
he says would, if found fossil in rocks, be taken by geologists to 
‘indicate a shallow estuary surrounded by forests. 
In my estimation these geologic pictures give no more correct a 
view of the modus operandi of the evolution of the geological 
features of the earth than does the strange view Dr. Carpenter 
credits some geologists with, that a sort of “See-Saw” has been 
___' Dredging Operations of U.S. Coast Survey, Steamer ‘“‘ Blake,” 1879, Letter 
No. 3, pp. 294-5, 
