212 WAVES OF THE SEA 



beach, and the action often proceeds as far as 

 the formation of isolated patches of shingle. 



The occasion upon which I saw the process pro- 

 ceeding best was during a heavy swell succeeding 

 a storm, when the wash of the breakers carried 

 the sand away in suspension. The shingle remain- 

 ing behind became concentrated in the manner illus- 

 trated by the photographs. The plate facing p. 214, 

 from a photograph, taken on a later occasion, and 

 about 4 miles farther east, shows more distinctly the 

 characteristic wedge-shape of the isolated patches 

 of shingle. If the process were to continue, these 

 patches would coalesce into a single ridge of 

 shingle. This sorting action of the waves is at 

 once taken advantage of by builders or others re- 

 quiring shingle, carts being sent to remove it before 

 the smaller waves and offshore winds have again 

 smothered it with sand. 



