ANNOTATIONS AND ADDITIONS. 45 



inland salt lake in North America, a question previously 

 raised by the well-informed American geographer, Tanner. 

 (Humboldt, Atlas Mexicain, planche 2 ; Essai Politique sur 

 la Nouvelle Espagne, T. i. p. 231, T. ii. pp. 243, 313, and 

 420 ; Fremont, Upper California, 1848, p. 9 ; and, also, 

 Duflot de Mofras, Exploration de TOregon, 1844, T. ii. 

 p. 40.) Gallatin says expressly, in the Memoir on the 

 Aboriginal Races in the Archseologia Americana, vol. ii. 

 p. 140, " General Ashley and Mr. J. S. Smith have found 

 the lake Timpanogo in the same latitude and longitude 

 nearly as had been assigned to it in Humboldfs Atlas of 

 Mexico." 



I have dwelt on the remarkable swelling of the ground 

 in the region of the Rocky Mountains, because, doubtless, 

 by its elevation and extent, it exercises an influence hitherto 

 but little considered, on the climate of the whole continent 

 of North America, to the south and east. In the ex- 

 tensive continuous plateau, Fremont saw the waters covered 

 with ice every night in the month of August. Nor is 

 the elevation of this region less important as respects the 

 social state and progress of the great United States of 

 North America. Although the elevation of the line of the 

 separation of the waters nearly equals that of the passes of 

 the Simplon (6170 French, or 6576 English feet), of the 

 St. Gothard (6440 French, or 6865 English feet), and of 

 the St. Bernard (7476 French, or 7969 English feet), yet 

 the ascent is so gradual, as to offer no obstacle to the use 

 of wheel carriages of all kinds in the communication between 

 the basins of the Missouri and the Oregon ; in other words, 



