144 



NATURE FOR ITS OWN SAKE 



Theform- 

 ing of 

 sand-dun**. 



grind of wave and bowlder on the base of the 

 cliff, until it is so eaten away that the top 

 heaved by frost falls into the sea by its own 

 weight. In either or any case, and however the 

 wear may take place, it is slow annihilation for 

 the cliff. The sea gains inch by inch. 



Bnt the shore is not subject to all loss and no 

 gain. Occasionally a great storm brings sand 

 in and heaps it up along the beach. This is the 

 beginning of the sand-dune the great protector 

 of the land against the sea. It must not be 

 conjectured, however, that the high dunes of 

 the Cape Cod shore or the low sand-banks of 

 the New Jersey coast are wholly the heaped-up 

 deposits of the waves. Dry sand will drift with 

 the wind very much like hard ball snow, as 

 anyone who has been on Sahara will testify. 

 Even the tourists at Cairo, who never go be- 

 yond the Mooski, will be able to say how many 

 times the Sphinx has been dug out of the 

 drifted sands of Egypt. Along the exposed 

 shore, where the winds are always restless, 

 the loose sands are kept in continual motion, 

 and it is the winds that round up and build 

 the hills and valleys of the sand-dunes. In 

 addition to the sands brought in by the sea, the 

 land breezes drift quantities of them down 



