The Mighty Deep 



of north and south thus seem to be exactly 

 reversed. 



Not long ago it was believed that the ocean's 

 floor might be a fairly close imitation of that 

 which we see on land. The differences, however, 

 have been found to be greater than was expected. 

 Perhaps it is not surprising, when one thinks 

 of the immense levelling power of water. 



That must be a firm make of rock which 

 can permanently resist the effect of sea waves 

 breaking upon or near the shore. And even 

 deeper down, where waves are not and currents 

 may be slow, some movement must still exist, 

 since the ocean is nowhere quite stagnant. 

 Such movements, no matter how gende, would 

 tend to shift all loose and soft substances. 



The ocean-bed is held to be generally flat, 

 though with gradual slopes here and there, 

 leading up or down to higher or lower levels. 

 Many submarine mountains rear their heads, 

 sometimes near the surface, sometimes above 

 it. In places high mountain-ridges run for a 

 long distance below the sea, with profound 

 depths on either side ; and these again often 

 show their peaks, forming groups of islands. 



Broad reaches of the ocean are between two 

 and three miles deep, and here and there spots 



22 



