lo THE OCEAN 



affording ample proof that not only once but 

 many times the islands have been raised and 

 sunk; each growth of coral indicating a period 

 of submergence and each layer of ash and lava 

 telling of a time when the blazing, molten 

 matter from the crater poured down and cov- 

 ered the marine growths which had been 

 raised from their ocean bed. 



Such sudden and immense alterations in the 

 islands of the world are not all happenings of 

 the dim and distant past. Even within a few 

 years large islands have been suddenly lifted 

 above the sea in the Pacific by some subter- 

 ranean upheaval ; in some cases to remain per- 

 manently, in others to disappear almost as 

 suddenly as they appeared. 



Knowing that such things take place above 

 the sea there is no reason to think that similar 

 great changes do not occur beneath the ocean, 

 and no doubt mountain-chains are formed, 

 vast chasms opened, peaks levelled and other 

 great alterations made in the ocean bed of 

 which we know absolutely nothing. Perhaps 

 the violent distant earthquakes which are fre- 

 quently recorded by our instruments may 



