GENERAL FEATURES OF THE EARTH. 25 



Unlike North America, South America has a broad ocean on the 

 north, — the North Atlantic in its longest diameter ; and, accordingly, 

 this northern coast has its mountain-chain reaching along through 

 Venezuela and Guiana. 



The drainage of South America, as observed by Professor Guyot, 

 is closely parallel with that of North America. There are, first, a 

 southern system, — the La Plata, — reaching the Atlantic toward the 

 south, between the converging east-and-west chains, like the Mis- 

 sissippi ; second, an eastern system, — that of the Amazon, — corre- 

 sponding to the St. Lawrence, reaching the same ocean just north of 

 the eastern mountain-border ; and, third, a northern system, — that of 

 the Orinoco. — draining the slopes or mountains north of the Amazon 

 system. The two Americas are thus singularly alike in system of 

 structure : they are built on one model. 



The relation of the oceans to the mountain-borders is so exact that 

 the rule-of-three form of statement cannot be far from the truth. As 

 the size of the Appalachians to the size of the Atlantic, so is the size 

 of the Rocky chain to the size of the Pacific. Also, As the height of 

 the Rocky chain to the extent of the North Pacific, so are the height 

 and boldness of the Andes to the extent of the South Pacific. 



(2.) Europe and Asia. — The land covered by Europe and Asia is 

 a single area or continent, only partially double in its nature ( (p. 13). 

 Unlike either of the Americas, it lies east-and-west, with an extensive 

 ocean facing Asia on the south ; and its great feature-lines are in a large 

 degree east-and-west. The Arctic Ocean is on the north ; the North 

 Atlantic is on the west ; the North Pacific on the east ; Africa and the 

 Indian Ocean are on the south. The Atlantic is the smallest ocean ; 

 the North Pacific next, — for its average depth is probably not over 

 13,000 feet (p. 12), and it is much encumbered by islands to the west- 

 of-south ; the Indian Ocean next, — for it is full 5,000 miles wide 

 in front of the Asiatic coast, and singularly free from islands. The 

 boundary is a complex one, and the land between the Atlantic and 

 Pacific over 6,000 miles broad. 



On the side of the small North Atlantic, there are the mountains of 

 Norway and the British Isles, the former having a mean height of 

 4,000 feet. On the Pacific side, there are loftier mountains, extending 

 in several ranges from the far north to southern China, — the Stano- 

 voi. Jablonoi, and Khingan ranges ; and, off the coast, there is still 

 another series of ranges, now partly submerged, — viz., those of Japan 

 and other linear groups of islands. These stand in front of the inte- 

 rior chain, very much as the Cascade Range and Sierra Nevada of the 

 Pacific border of America are in advance of the summit-ridges of the 

 Rocky Mountains, and both are alike in being partly volcanic, with 

 cones of "reat altitude. 



