442 , Expedition^ &c. 



lous cities .springing up in the most depressed parts of that 

 valley, and those, who Hvt^ ht-reai"ter, will probably see there, 

 a large portion of the population, the civilization, and wealth 

 of America. 



Explanation of the Plate, 



In illustration of the foregoing remarks we offer two trans- 

 verse sections, adapted to the scale of elevation by Maj. 

 Long. In the delineation it will be perceived little regard has 

 been paid to the horizontal scale. The intention being to 

 exhibit an outline of our idea of the structure of the different 

 groups of mountains, some wide and uninteresting piains, 

 as that between 5*^ and 12*^ west, in the northern, and 11^ 

 and 13'' in the southern section have been omitted. Particu- 

 lar attention has been bestowed in adapting the delineations 

 to the scale of elevation, which, as will be perceived on in- 

 spection, is divided into three parts differently graduated. 



The inclinations, indicated by the lines between the dif- 

 ferent formations, are not to be considered applicable to all 

 the strata composing those formations, as in the instance of 

 the coal in the southern section of the Alleghanies, the strata 

 of sandstone and bituminous shale are nearly horizontal, 

 but occupy the several elevations indicated by the inclined 

 line in the section; the lines, therefore, may l»e considered 

 as marking the position of formations, rather than the inclina- 

 tion of strata. 



The inclination of the strata in the southern section of the 

 Ozark mountains is usually towards the south, or southeast, 

 and more irregular in direction, than in the Alleghanies. 



It is proper to remark that the coal strata, in the northern 

 section of the Alleghany mountains, are very extensive, and 

 rise nearer to the highest elevations, than in the southern, 

 though, in the delineation, this has not been particularly 

 represented. 



