THE SURFACE OP THE EARTH. 



which are frequently volcanic, it is continued in a direction 

 parallel to the western coast of the continent, until it terminates 

 in the Tierra del Fuego, the southern point of which is called 

 Cape Horn. 



93. Andes of Pafagonia and Chili. Between this point and 

 Chili, returning northwards, the slopes of the Andes descend to the 

 waters of the Pacific, the coast being lined with numerous islands 

 and indented with arms of the sea, an outline which indicates 

 the continuation of the mountain range below the waters of the 

 ocean ; the capes, promontories, and islands being merely the 

 ridges and summits of the spurs and peaks of the main range, 

 whose bases are established at the bottom of the ocean. Pro- 

 ceeding northward, the general direction of the chain takes a 

 more inland course, leaving between its base and the sea a long 

 and flat tract of land, whose coast is no longer broken by the 

 indentations just described, is completely destitute of islands, and 

 forms no shelter for navigators. 



94. Andes of Bolivia and Peru. Still proceeding northward 

 and approaching the Peruvian territory, the general elevation of 

 the Andes rapidly increases, and their summits rise to vast 

 elevations above the snow-line ; among these is the Nevado 

 Aconcagua, having an elevation of 24000 feet, and being the most 

 lofty point of the western continent. This peak was originally 

 volcanic, but within historic record it has not been active. 



About latitude 24 south, the chain takes the name of the 

 Peruvian Andes, and here it is at a considerable distance from 

 the western coast, from which it is separated by a sandy 

 desert. 



95. Cordilleras. North of 21 lat. south, the chain of the Andes 

 diverges into two or three separate ridges, called Cordilleras, 

 which are connected at different points by their common spurs 

 issuing transversely to their directions, so as to form a net- work 

 enclosing numerous valleys, the bottoms of which are elevated to 

 a considerable height above the level of the sea, forming in many 

 cases plateaux and tablelands of great extent, the most remark- 

 able of which is that of Desaguadero, which measures 400 miles 

 in length, with a breadth varying from 30 to 60, and a general 

 elevation of nearly 13000 feet above the level of the sea. Vast 

 peaks are thrown up from the borders of this immense plateau to 

 the height of more than 8000 feet above the surface, rising far 

 above the snow-line. 



96. Potosi. Upon this extensive tableland, whose area is 

 three times that of Switzerland, stands Potosi, the highest city in 

 the world, at an elevation of 13330 feet above the level of the 

 sea, with a population of 30000. This city is built on the 



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