Masterpieces of - Science 



the beach, it is easy to see how these suffer by the 

 constant dash of the waves. Rain, frost, and 

 other atmospheric agents, playing their part in 

 the work of destruction, attack the cliff and dis- 

 lodge masses of rock which come tumbling down 

 to its base, where they accumulate as a line of 

 rubbish. As soon as the fragments are brought 

 within reach of the waves, they are rolled against 

 the cliff, bruising and battering the face of the 

 rock, while the fragments themselves are apt to 

 get shivered in the fray. 



During violent gales the breakers acquire 

 unusual power, and are able to move rocks of 

 enormous weight. On the western coast of 

 Britain, where the Atlantic breakers roll in upon 

 the shore, they have been known to exert a 

 pressure of between three and four tons on every 

 square foot of surface exposed to their fury. 

 Even in summer, these waves break upon the 

 coast with a pressure of about six hundred pounds 

 per square foot; and, in winter, this force is often 

 trebled. It is easy to believe that such masses 

 of moving water can carry with them huge blocks 

 of stone, and hurling these against the shore, can 

 breach it just as effectually as though it were at- 

 tacked by the blows of a battering-ram. In 

 fact,, whether in storm or in calm, a cannonade, 

 more or less sharp, is constantly kept up against 

 the coast, the ammunition being supplied by the 

 ruins of the coast itself. 



Were the waves to break upon the shore with- 

 out the aid of any fragments of rock, the mere 

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