CHAPTER XV 



THE CONTINENTAL AREA 



354. Crest of the World Ridges. (Read 214, 251, 

 255, 256.) The five largest islands or peninsulas in which 

 the crests of the World Ridges break through the uniform 

 covering of the hydrosphere are termed continents, and 

 designated by the names Eurasia, Africa, North America, 

 South America, and Australia. They are distinguished from 

 other islands and peninsulas by size alone, Australia being 

 ten times larger than New Guinea, and Africa ten times 

 larger than Arabia, these being the greatest island and 

 peninsula not called continents. The elevated region round 

 the South Pole is crowned by the unexplored and scarcely 

 discovered continent of Antarctica. The land mass of 

 Eurasia is conveniently supposed to consist of the two 

 " continents " of Europe and Asia, and if this be allowed, 

 we find that the six known continents group themselves into 

 three pairs. North and South America share the Western 

 World Ridge ; Asia and Australia, on the eastern limb of the 

 Eastern World Ridge, lie diametrically opposite ; while 

 Europe and Africa occupy the western limb of the Eastern 

 World Ridge, diametrically opposite the great Pacific basin. 

 Until the Tertiary period, when the heights of Central Asia 

 were upheaved, the Indian Ocean stretched to the Arctic 

 Sea ; and even in Quaternary times Europe and Asia were 

 separated by a broad channel of water between the Medi- 

 terranean and the Arctic Sea. The prevailing continental 

 form is a south-pointing triangle. In each pair of continents 



