118 The Andes axd the Amazon. 



Guiana have neither volcanic nor snow-clad peaks.* Like 

 all the dry land which first appeared, these primitive moun- 

 tains on the Atlantic border trend east and west. The re- 

 sult of this position is a triple river system — the Orinoco, 

 Amazon, and La Plata, draining three immense plains — 

 the llanos of Venezuela, the sylvas of Brazil, and the pam- 

 pas of the Argentine EepubHc. The continuity and extent 

 of these vast depressions are more remarkable even than 

 the height and length of the mountain chains.f 



Such are the characteristic f eatm-es of South America ; 

 they are not repeated in any other continent. :j: Not one 

 feature could be changed without destroying those peculi- 

 arities of soil and climate which so remarkably distinguish 

 South America. Its position on the equator places it in 

 the path of the vapory trade winds, which continually 

 sweep over it westward till they strike the Andes, which, 

 like a great condenser, roll a thousand streams eastward 

 again to feed the mighty Amazon. So effectual is that 

 barrier, not a drop of moisture passes it, and the trade wind 

 is not felt again on the Pacific till you are one hundred 



* "The interior plateau of Brazil (says Dr. Lund) is composed of horizon- 

 tal strata of the transition period, which are nowhere covered with the sec- 

 ondary or tertiary formations." The highest point in Brazil is 5755 feet. 

 Darwin speaks of "some ancient submarine volcanic rocks (in the province 

 of La Plata) worth mentioning, from their rarity on this eastern side of the 

 continent." With the exception of the coast of Venezuela, the eastern sys- 

 tem is little exposed to earthquakes. 



t These three plains constitute four fifths of all South America east of the 

 Andes. The west slope of the Ecuadorian Andes is about 275 feet per mile ; 

 on the east it is 125 feet. 



X There is, however, a striking coincidence between the mountain and river 

 systems of the northern and southern continents of this hemisphere. Thus, 

 The Andes represent the Eocky Mountains, 

 ' ' Highland of Guiana represent the Canadian Mountains. 

 " " Brazil " Appalachian " 



" Amazon " Saskatchewan. 



" La Plata " Mississippi. 



" Orinoco " Mackenzie. 



