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mine of which I have seen any record, is only about a 
twenty-second part of ten miles. Twenty-two such shafts 
end to end with each other, would be required to pierce the 
earth's surface to that depth. Then if we take the estimated 
thicknesses of the strata that have been classified, that proves 
far too much. Those formations which are now placed below 
the Silurian, are described as fifteen miles in thickness in 
themselves alone ! Were we to go by the estimated thicknesses 
of the rocks, and to imagine that at one time they all lay one 
over the other at any one point on the globe, we must con- 
clude that we know something like a hundred miles down, 
instead of ten ! Then suppose that we take a mountain and 
let it even be 20,000 feet high, that is, nearly four miles, 
who shall tell us what is in the interior of that mountain on 
a level with the plains at its feet ? We are told that “ it may 
appear inconceivable to a beginner, how mountains several 
thousand feet high, can have become filled with fossils from top 
to bottom;” but our difficulty is not with the conception, but 
with the entire absence of proof that there are any such 
mountains on earth. We may be perfectly satisfied that the 
surface of the mountain, even to its summit, is formed of 
sedimentary strata and contains fossils ; but this is only a 
surface matter of comparatively a few feet, while we are 
seeking for some scientific grounds on which to found the 
belief that geologists know the crust of the planet to a 
vertical depth of ten miles ! But we have the “ dip " and 
bend of strata going down from the surface and coming back 
to it again. Say we take a Laurentian rock that rises to the 
surface, at a certain point, and consequently, if we trace it 
back from that point, it “ dips '' away towards the earth's 
centre at a certain angle. We pass along in the direction of 
this “ dip " till we at last believe that we meet with this 
same rock rising to the surface again, we shall say at a similar 
angle to that at which it went down. Wbrking on this angle, 
and on the distance between the two points at which the rock 
rises to the surface, we draw a “ section " of the crust of the 
earth which accords with these data. We have a magnificent 
bend in the bosom of which to “ fill in '' any amount of 
newer formations, and at the point at which the bend is the 
deepest, we have a great deal more, we suspect, than ten 
miles ! Our difficulty here again is, not that we have not 
proved enough, but that we have proved a great deal too 
much ! Wo begin to be deeply thoughtful on the problem, 
as to whether, it geologists had known the crust of our globe 
to half the distance we have reached, they could ever have 
fallen into . those mistakes as to its character which have 
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