Valley of the Mission. 



I have thus examined in detail the arguments adduced in sup- 

 port of the superior temperature of the climate of the Mississippi, 

 to that of the Atlantic coast, under similar parallels of latitude. 

 This was not only essential to a full developement of the subject, 

 but was due to the talents, ingenuity, and high reputation of the 

 authors in whose works they are contained. 



I come now to the second division of this essay, which is to 

 prove that the climate of the Mississippi valley, dues not material- 

 ly differ from that of the Atlantic coast. This I shall endeavour 

 to do, first, by a comparison of thermometrical observations; and 

 secondly, by a comparison of the flowering seasons of plants. 



As the temperature of a climate, although it depends chiefly up- 

 on the latitude, is more or less influenced by situation, elevation, 

 and exposure, it may be proper to give some account of the natu- 

 ral formation of the different portions of country, which are the sub- 

 jects of comparison. In doing this, I shall confine myself to a belt 

 of about three hundred and fifty miles in width, bounded on the 

 north by the parallel of latitude 43° N., and on the south by that 

 of 37° N. This will not only embrace the territory east and west 

 of the Alleghanies, whose climate is said to differ,* but also that 

 in which the most correct observations have been made. 



This belt is bounded on the east and west, by the Atlantic and 

 Pacific oceans, and at nearly equal distances from these, is crossed 

 by two chains of mountains, which form a great valley of nearly 

 three thousand miles in extent. It is therefore naturally divided 

 into five regions. 1. The eastern littoral. 2. The eastern moun- 

 tainous. 3. The great alluvial. 4. The western mountainous : 

 and 5. The western littoral. 



The eastern littoral region is washed on the east by the Atlantic 

 ocean, and is abundantly watered by streams which generally have 

 a southerly course. It is from 150 to 250 miles in breadth. Its 

 surface, although occasionally broken by ranges of hills, is in the 

 main level. It is for the most part settled and cultivated, but still 

 contains many extensive wastes and forests. 



