102 INTRODUCTION. 



consists of the ranges known as the Rocky Mountains, 

 running nearly parallel with the coast of the Pacific 

 Ocean, of various elevation, but the highest peaks 

 rising beyond the limits of perpetual frost and snow. 

 These separate the waters running into the Pacific 

 Ocean from those flowing into the Mississippi River, 

 and Gulf of Mexico. The second system consists of 

 the Appalachian ranges, which rise from an elevated 

 table-land that makes up nearly half of their whole 

 elevation, the summits occasionally reaching an altitude 

 of six thousand, or even six thousand five hundred feet 

 above the sea, but presenting a mean height of from 

 two thousand to two thousand five hundred feet. They 

 extend in a north-east and south-west direction from near 

 the St. Lawrence river to Alabama, and form a barrier 

 between the waters that flow westward to the Missis- 

 sippi river and the Gulf of Mexico, and those that 

 flow directly into the Atlantic Ocean. At their south- 

 ern extremity they incline towards the south-west, and 

 terminate before reaching the Gulf of Mexico, thus 

 permitting the low alluvial lands of the southern Atlan- 

 tic coast to unite with the lands of the same character, 

 which form the southern part of the valley of the 

 Mississippi. The great regions formed by these par- 

 allel systems are the followmg : 



1. The Pacific Region, extending between the 

 coast of the Pacific Ocean and the Rocky Moun- 

 tains. Of this, as well as of the elevated plat- 

 form or table-land from which these mountains 



