CONTINENTAL RING 51 



ment signalised by earthquakes, subsidences, and volcanic 

 action. 



The Atlantic coast is not fronted by mountain chains ; 

 its coasts correspond with great lines of fracture, along 

 which the once-existent land has sunk down to form the 

 ocean floor. It is by such subsidences that both the 

 Atlantic and Indian Oceans are supposed by Suess to 

 have been enlarged. 



There is independent evidence to show that large parts 

 of the existing Atlantic and Indian Oceans were at one 

 time dry land ; the character of many geological deposits, 

 the distribution of the fossil organisms they contain, as 

 well as certain facts in the distribution of existing 

 animals and plants, all combine in favour of this 

 view. 



Between the Pacific on the one hand and the Indian 

 and Atlantic Oceans on the other, a terrestrial globe 

 shows us a nearly continuous ring of continental land, 

 North and South America, the Antarctic Continent, Aus- 

 tralia, the East Indian islands (probably the fragmentary 

 remains of a once much more continuous area) , and finally 

 Asia. 



This is the bulging ring produced, as Mr. Jeans 

 imagines, by the crushing together of the two hemi- 

 spheres. 



The symmetry of the earth, at least as to the distribu- 

 tion of land and sea, would thus appear to be less marked 

 in relation to its axis of rotation than to one of its equa- 

 torial diameters. This diameter, indeed, is that we have 

 already indicated as passing through the middle of Africa. 

 From a general consideration of terrestrial symmetry I 

 was led* to place its intersection with the surface in 

 lat. 6 N., long. 28 E., or between the positions obtained 



* " The Figure of the Earth/' Quart. Journ. Geol. Soc., vol. lix.* 

 pp. 180-188, 1903, 



