in the Geological History of North America. 341 
ocean, the higher the mountains on its borders, the deeper the 
Oe g 
___ fractures and displacements there, and the vaster the outflow of 
In a section of the North American continent, drawn toa scale 
twelve feet long, one-ninth of an inch will stand for an altitude of 
un 
10,000 feet; one-sixteenth of an inch for the White Mountains, 
and about three-tenths for the Himalayas. 
eastward the power was comparatively moderate, gently ea 
w 
ciency of the great organizing forces. te 
_, Glance AGW at ‘Amuciti geological history from this point hs 
t of the nine ah AS 
the first in th logical series. Such an area (see Chart, 
extends Seith, Rorthetn New York and Canada, north-west to 
the Arctic Ocean, lying between the line of small lakes (Slave, 
Winnipeg, &e.) and Hudson Bay. East and west, it dips under 
+. atriki I have 
- * The contrast with Europe in this respect is striking, and accounts, as 
Said, (Address, é:c,, p. 811,) for the greater simplicity of North American Geology. 
