THE 1U6SISSIPPX BASIN. 
355 
1 - — The basin op the Mississippi and op Canada. 
.A.n able geologist, Mr. Edwin James, lias recently shewn 
that this basin is comprehended between the Andes'of New 
lMexico,or Upper Louisiana, and the chains of the A Ueghanies 
which stretch northward in crossing the rapids of Quebec. 
It being quite as open northward as southward, it may be 
designated by the collective name of the basin of the Mis- 
sissippi, tlie Missouri, the river St. Lawrence, the great lakes 
of Canada, the IMackenzie river, the Saskatehawan, and the 
coast of Hudson’s Ba^. The tributary streams of the lakes 
and those of the Mississippi are not separated by a chain of 
mountains running from east to west, as traced on several 
maps ; the line of partition of the waters is marked by a 
slight ridge, a rising of two counter-slopes in tlie plain. 
There is no chain between the sources of the JTissouri and 
the Assineboine, which is a branch of the lied Eiver and of 
Hudson’s Bay. The surface of these plains, almost all 
savannah, between the polar sea and the gulf of Mexico, 
is more than 270,000 square sea leagues, nearly equal to the 
area of the w'hole of Europe. On the north of the parallel 
of 42°, the general slope of the land runs eastward; on the 
south of that parallel, it inclines southward. To form a 
precise idea how little abrupt are these slopes we must 
recollect that the level of Lake Superior is 100 toises ; that 
of Lake Erie, 88 toises, and tliat of Lake Ontario, 36 toises 
above the level of the sea. Tlie plains around Cincinnati 
Cat. 39° 6') are scarcely, accordhig to Mr. Drake, 80 toises 
of absolute heiglit. Towards the west, between the Ozark 
mountains and the foot of the Andes of Upper Louisiana 
yEocky Mountains, hit. 35° — 38°), the basin of the Mississippi 
is considerably elevated in the vast desert described by M r. 
IN'uttal. It presents a scries of small table-lands, gradually 
rising one above another, and of which the most westerly 
(that nearest the Eocky Mountains, between the Arkansas 
and the Padouca), is more than 450 toises high. Major 
Bong measured a base to determine the position and height 
of James Peak. In the great basin of the Mississippi, the 
line that separates the forests and the savannahs runs, not, 
as may be supposed, in the manner of a parallel, but like the 
Atlantic coast, and the Alleghany mountains themselves, 
from N. E. to S.\V.,from Pittsburg towards Saint Louis, and 
2 a2 
