73 



RIVERS. 



THE size and course of rivers are chiefly determined by the height and 

 direction of the mountain chains, in which they originate. Thus the 

 Rhine, the Danube, and the Rhone, the largest rivers in Europe, take 

 their rise in the Swiss Alps. The great rivers of Asia have their 

 origin in some of its lofty central chains. The northern rivers, the 

 Irtish, Ob, Yenisei, and Lena may all be traced to the Altai; the Ho- 

 yang-hoand Yangtse Kiang of China, arise in the mountains forming the 

 eastern abutment of the central table land of Asia; whilst the southern 

 ramparts of that table land contain the sources of the great river of 

 Cambolia, the Irowaddy, the Brahmaputa, the Ganges, and the Scind 

 or Indus. In Africa, the Nile has one of its sources in the lofty 

 mountains of Abyssinia, and the other in the more distant central chain; 

 the Niger rises in the western chain, runs eastward, is deflected in the 

 kingdom of Houssa towards the south and west, and finally pours its 

 waters into the Atlantic in the Gulf of Guinea. In America the Madalina 

 and Maranon, spring directly from the Cordillera of the Andes, that 



-" Giant of the western star 



With meteor standard to the winds unfurl'd, 



Looks from his throne of clouds o'er half the world," 



which also contain the principal sources of the Orinoco ; whilst the more 

 sluggish streams of the Paraguay and Parana derive their waters from 

 the lower transverse chain, stretching to the coast of Brazil. In North 

 America the Arkansas, Red River and Missouri, the great feeders of the 

 Mississippi, spring from the northern Andes, where also are the sources of 

 the Columbia to thewest,and of the Saskatchewan the principal stream, which 

 flowing into Lake Winnipeg, becomes thus a part of that vast chain of 

 lakes or seas, the outlet of which is the St. Lawrence. The channels of 

 rivers are partly produced by the action of their own waters; but, 

 undoubtedly, also by some cause which disturbs the original arrangements 

 of the solid materials of the earth. Thus earthquakes have often opened 

 passages for rivers, through barriers of rocks and mountain chains. 

 Rivers occupy the lowest parts of valleys through which they flow, and 

 when they are very large, their declivities are generally small. The 

 surface of the Maranon, 3,000 miles from the sea, has only an elevation of 



