CHAPTER 



III. 



GENERAL DESCRIPTION OF THE COUNTRY. 



8U1TABLKXKSS AS A BOUXDARY.— GREAT PLATEATJ OF AMERICA AND MOrXTAlN RANGES-— l>ErRE^IO>- OF MOt'NTAlNS NEAR IHfl 



PARATXEL OF THIRTY-TWO DEGREES NORTH XATITrBE. — GEOGRi 



;al errors. 



FER 



LAKES. — SAND 



DESERT8. 



-TEGETATION AND AGRXCVLTERAIi CAP ACITY. —CHARACTER OF THE RIO BRAVO.— RAIL\y AY.— ASTRONOMICAL DE- 



TERMINATIONS. 



The botindary between the United States and Mexico, extends entirely across the continent 



from ocean to ocean. 



mouth 



the San Pedro, or Devil's river of Texas, makes a boundary, which, in the absence of extradition 



svs, must 

 In other 



determined 



resist what appears to me the inevitable expansive force of her institutions and peoj^le, and set 

 limits to her territory before reaching the Isthmus of Darien, no line traversing the continent 

 could probably be found Avbich is better suited to the purpose. 



In this 



much 



religion, 



mark 



customs, and physical wants, should be separated by lines 



geography. 



The boundary is embraced in the zone separating the tropical from the temperate and more 



northern regions. Here, waters unite, some of 



from 



To the north of this zone, the showers from the tropics cease to refresh the earth, and within 

 it all the flora and fauna which characterize the northern and temperate regions almost dis- 

 appear, and are not entirely supplanted by those of the tropics. 

 It is indeed a neutral region, having peculiar characteristics, so different as to stamp ux3on 



vegetable and animal life features of its own. 

 The most remarkable and apparent differe 



much 



difference in its botanical and zoological productions, is the hygrometric state of the atmosphere ; 

 for while the plants and animals assume new forms in life, the crust of the earth, the soil, and 



many 



the American continent. 



It is very arid ; but this is also the character of all the country north of the tropics, and west 



e 100th meridian of longitude, until you reach the last sl( 

 im exceeding 200 miles in width, and sometimes not more 



a narrow belt, 

 The zone extending 



from the Gulf of Mexico to the Pacific, embracing the boundary, contains a large proportion of 

 arid lands ', yet this dry region is, perhaps, narrower on the line of boundary than on any por- 

 tion of the continent north of it, within the limits of the United States, and is occasionally re- 



summer 



to the north. 



