MOUNTAIN RANGES. 
207 
ain ranges, which divide the country into three 
distinct natural sections. These may be called the 
Atlantic Slope, the Mississippi Valley, and the Pa- 
cific Slope. The Alleghany or Appalachian range 
is remarkable chiefly for its length, extending from 
Canada on the north to Alabama on the south, a 
distance of more than 1200 miles ; while its mean 
average height is not more than 2500 feet, and more 
than half of this consists of the height of the mount- 
ain ridges above their bases, and the other, of the 
height of the adjoining country above the sea. 
About midway between the Atlantic and the Mis- 
sissippi lies a vast table-land, extending from the 
rivers of Alabama and Mississippi to the great 
lakes and the St. Lawrence, occupying the western 
part of the Atlantic states, and the eastern part of 
the adjoining states of the Mississippi Valley. 
Along this table-land extend five or six parallel 
mountain chains, of which the most remarkable are 
the Blue Ridge, the Alleghany Ridge, the Wickany, 
and the Cumberland Mountains. The White Mount- 
ains of New-Hampshire, which are usually consid- 
ered as a prolongation of the Blue Ridge, contain 
some of the loftiest summits east of the Mississip- 
pi, Mount Washington being 6428 feet above the 
sea ; the Black Mountain, in North Carolina, which 
is in the range of the Blue Ridge, is ascertained to 
be 6476 feet in height, while the highest point of 
the Alleghany is not over 3000 feet above the sea. 
The Rocky Mountains have been sometimes call- 
ed the Andes of North America, or the Chippeway- 
an system ; and they extend from the Isthmus of 
Panama, parallel with the Pacific, almost to the 
Ar<itic Sea ; having an average height of 8000 feet 
above the ocean, or 5000 above the level of their 
base. Their highest summit has usually been 
computed at about 12,000 feet ; though Professor 
* Outlines of Geology, p. 13. 
