TUE MISSISSIPPI BASIN. 355 



I. THE BASIN OF THE MISSISSIPPI AND OF CANADA. 



An able geologist, Mr. Edwin James, has recently shewn 

 that this basin is comprehended between the Andes of New 

 Mexico,or Upper Louisiana, and the chains of the Alleghanies 

 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, the Missouri, the river St. Lawrence, the great lakes 

 of Canada, the Mackenzie river, the Saskatchawan, and the 

 coast of Hudson's Bay. 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 the plain. 

 There is no chain between the sources of the Missouri and 

 the Assineboine, which is a branch of the Bed River 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 whole 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 that of Lake Ontario, 36 toises 

 above the level of the sea. The plains around Cincinnati 

 (lat. 39 6 X ) are scarcely, according to Mr. Drake, 80 toises 

 of absolute height. Towards the west, between the Ozark 

 mountains and the foot of the Andes of Upper Louisiana 

 (Rocky Mountains, lat. 35 38), the basin of the Mississippi 

 is considerably elevated in the vast desert described by Mr. 

 Nuttal. It presents a series of small table-lands, gradually 

 rising one above another, and of which the most westerly 

 (that nearest the Kocky Mountains, between the Arkansas 

 and the Padouca), is more than 450 toises high. Major 

 Long 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. W., from Pittsburg towards Saint Louis, and 



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