8 



THE SEA SHORE 



desolate western coasts. At such times we delight to watch the 

 distant waves as they approach the shore, to see how they become 

 gradually converted into the foaming breakers that dash against the 

 standing rocks and wash the rattling pebbles high on the beach. 

 The powerful effects of the sea in wearing away the cliffs are now 

 apparent, and we can well understand that even the most obdurate 

 of rocks must sooner or later break away beneath its mighty waves. 

 The extreme mobility of the sea is displayed not only by the 

 storm waves, and by the soft ripples of the calm day, but is seen 



FIG. 6 BREAKERS 



in the gentle currents that almost imperceptibly wash our shores, 

 and more manifestly in the perpetual motions of the tides. 



This last-named phenomenon is one of extreme interest to the 

 sea-side rambler, and also one of such great importance to the 

 naturalist that we cannot do better than spend a few moments in 

 trying to understand how the swaying of the waters of the ocean 

 is brought about, and to see what determines the period and 

 intensity of its pulsations, as well as some of the variations in 

 the daily motions which are to be observed on our own shores. 



In doing this we shall, of course, not enter fully into the tech- 



