278 The Realm of Nature CHAP. 



PERCENTAGE AREA OF CONTINENTS SLOPING TO EACH OCEAN 



357. South America being the most typical continent 

 may be first described. The triangular outline is modified 

 by a large outcurve of the northern half of the west coast 

 north of 20 S., and on the middle of the east coast by a 

 more prominent outcurve culminating in Cape San Roque. 

 Its greatest length, nearly along the meridian of 70 W., is 

 4800 miles, from Point Gallinas on the Caribbean Sea in 

 13 N. to Cape Horn on the Southern Ocean in 56 S. 

 The greatest breadth from west to east is 3300 miles along 

 the parallel of 5 S., between Point Parina (82 W.) and 

 Cape San Roque (35 W.) A group of rocky islands, the 

 Chonos Archipelago, runs for 1200 miles close to the fjord- 

 grooved west coast at its southern extremity, and a tortuous 

 channel separates the south-eastern tip, Tierra del Fuego, 

 from the mainland. The average elevation of the continent 

 is almost exactly that of the whole continental area. 



358. The Andes. The main axis of South America lies 

 close to the west coast along the crest of the Andes, which 

 form the longest mountain system, unbroken by passes of 

 low elevation, in the world. The short slope to the Pacific 

 varies from 30 to 150 miles in breadth ; the long slope to 

 the Atlantic is in parts 3000 miles wide. A mountain 

 system is not a ridge, but a region showing diversities of 



