152 



THE OPAL SEA 



Reefs and 



sunken 



rocks. 



Sands of 

 the shore. 



Tinra and 



necks of 

 land. 



ing away all trace of the accident. They smooth 

 and scour and roll the broken fragments into 

 deeper water until nothing but a stump of rock 

 is left. Long years afterward the once lofty 

 pinnacle appears on the sailing charts as a reef 

 or sunken rock; and as you drive by it in a 

 catboat you may notice a flattening of the water 

 just there and a tangle of green sea weed that 

 sways and rolls with each movement of the 

 wave. 



But is the sea always the gainer? Is there 

 no compensation made to the land? What be- 

 comes of the fallen blocks of stone — the disin- 

 tegrated cliff? All the sands of the pocket 

 beaches, of the bars, and spits, and shallow sea- 

 beds make answer. They themselves are but 

 the granulated bowlders of the shore. As they 

 are ground to sand and gravel the waves scat- 

 ter them along the sickle-shaped beaches; or, 

 quite as often, the currents lead them out to 

 sea and heap them over sunken reefs. Drift 

 upon drift they gather until after a long 

 time — for the processes of nature are slow — 

 they become a bar or neck of land called a 

 shoal. At low tide this bar appears above the 

 water — a dark, flat strip where shore-birds con- 

 gregate and sea weeds cling. Eventually it lifts 

 high enough to be above the tide, grows into a 



