in the Geological History of North America. 337 
ay near the equator is 20,000 feet. In Australia, the Austra- 
lian Alps, as they are called, are on the east fronting the Pacific, 
here the wider of the bordering oceans. 
Thus all over the world, the highest mountains stand fronting 
the largest and deepest oceans; and the “rule of three” state- 
ment of the fact scarcely conveys a wrong impression. 
2. We observe further that the coasts are in general so turned 
as to face the widest range of ocean. e Appalachians with 
the neighboring coast do not face northeast towards the Euro- 
pean continent, but southeast, towards the great opening of the 
Atlantic between America and Africa. So on the west side of 
orth America the Pacific coast faces, not towards Asia, but 
southwest, where the broadest range of ocean is before it. 
3. Consider now a little more closely the structure of these 
ocean borders. How is it as to the effects of heat or volcanic 
action ? 
In North America, on the side of the smail ocean, the Atlantic, 
we find metamorphic rocks, some trap dykes, and a few tepid 
Beings. On the side of the great ocean, the Pacific, all these 
p : 
of the globe, while basaltic floods have buried out of sight 
almost all other rocks over a considerable part of the country. 
Mount St. Helens, Mount Hood, Mount Shasta, and a dozen 
others, twelve to eighteen thousand feet high, make a majestic 
le of fire mountains not yet wholly extinct. May we not then 
Say, As the size of the Atlantic to the action of heat on the Atlantic 
— is the size of the Pacific to the action of heat on the Pacific 
In South America, there is a direct repetition of the same facts 
on a still grander scale: the Brazilian side, with metamorphic 
ks and no voleanoes; the Pacific side, with voleanic heights 
of 20,000 feet and upward. 
ern Ocean and not simply on the narrow Atlantic; the volea- 
ee are at the junction of the two lines, n or near the Bight of 
lafra, 
_4. Again, these effects of heat are confined mostly to the re- 
gion between the crest of the border mountains and the ocean, 
ards 
Tador to Georgia. is si : 
diminishes oes westward. So on the Pacific side: the great 
SECOND saa we XXII, NO. 66.—NOV., 1856. 
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