364 THE STORY-BOOK OF SCIENCE 



solve the air necessary to their animal and vegetable 

 population. For the ocean of waters, as for the at- 

 mosphere or ocean of air, there is need of a salutary 

 agitation of tempests that churn up, renew, and 

 vivify the waters. 



"The wind disturbs the surface of the ocean. If 

 it comes in gusts, it creates waves that leap with 

 foaming crest and break against one another. If 

 it is strong and continuous, it chases the waters in 

 long swells, in waves or surges that advance from 

 the open in parallel lines, succeed one another with 

 a majestic uniformity, and one after another rush 

 booming on to the shore. These movements, how- 

 ever tumultuous they may be, affect only the surface 

 of the sea; thirty meters down the water is calm, 

 even in the most violent storms. 



"In our seas the height of the biggest waves is not 

 more than two or three meters.; but in some parts of 

 the South Sea the waves, in exceptional weather, 

 rise to ten or twelve meters. They are veritable 

 chains of moving hills with broad and deep valleys 

 between. Whipped by the wind, their summits 

 throw up clouds of foam and roll up in formidable 

 volume with a force sufficient to shatter the largest 

 vessels under their weight. 



"The power of the waves borders on the pro- 

 digious. There, where the shore, rising vertically 

 from the water, presents itself fully to the assaults 

 of the sea, the shock is so violent that the earth trem- 

 bles under one's feet. The most solid dikes are de- 

 molished and swept away ; enormous blocks are torn 



