THE WORK OF THE OCEAN. 327 



The bed of the ocean, hke the face of the land, is affected by eleva- 

 tions and depressions, and its deepest points are about as far below its 

 surface as the highest mountains are above it. There are areas of the 

 Bea bottom which, as a whole, may be compared to the plains of the 



^ 





Fig. 296. — General relations of ocean basins to the lithosphere. Lat. 20° S. Depth 

 of the water (black) and height of land exaggerated ten times. (Data from Murray, 

 Scot. Geogr. Mag., Vol. XV, 1899.) 



land, and others which may be likened to plateaus, and the lines of 

 gradation between them are as "ndistinct as they often are on the land. 

 There are mountain peaks, chiefly of volcanic origin, and depressions 

 comparable to the great basins on the land. But apart from these gen- 

 eral features, there is little in common between the topography of the 

 sea bottom and that of the land. Mountain systems are, for the most 



