58 THE HISTORY OF THE NORTH ATLANTIC 



convenient distance in space, and scrutinizing its features as it 

 rolls before him, we may suppose him to be struck with the 

 fact that eleven-sixteenths of its surface are covered with water, 

 and that the land is so unequally distributed that from one 

 point of view he would see a hemisphere almost exclusively 

 oceanic, while nearly the whole of the dry land is gathered in 

 the opposite hemisphere. He might observe that large portions 

 of the great oceanic areas of the Pacific and Antarctic Oceans 

 are dotted with islands — like a shallow pool with stones rising 

 above its surface — as if the general depth were small in com- 

 parison with the area. Other portions of these oceans he 

 might infer, from the colour of the water and the absence of 

 islands, cover deep depressions in the earth's surface. He 

 might also notice that a mass or belt of land surrounds each 

 pole, and that the northern ring sends off to the southward 

 three vast tongues of land and of mountain chains, terminating 

 respectively in South America, South Africa, and Australia, 

 towards which feebler and insular processes are given off by 

 the antarctic continental mass. This, as some geographers 

 have observed, ^ gives a rudely three-ribbed aspect to the earth, 

 though two of the ribs are crowded together, and form the 

 Eurasian mass or double continent, while the third is isolated 

 in the single continent of America. He might also observe 

 that the northern girdle is cut across, so that the Atlantic 

 opens by a wide space into the Arctic Sea, while the Pacific is 

 contracted toward the north, but confluent with the Antarctic 

 Ocean. The Atlantic is also relatively deeper and less cum- 

 bered with islands than the Pacific, which has the highest 

 ridges near its shores, constituting what some visitors to the 

 Pacific coast of America have not inaptly called the " back of 

 the world," while the wider slopes face the narrower ocean. 

 The Pacific and Atlantic, though both depressions or flat- 



^ Dana, *' Manual of Geology," introductory part. Green, '* Vestiges 

 of a Molten Globe," has summed up these facts. 



