374 



THE BOTTOM OF THE SEA. 



causes an inclined plane to be formea, uj) whii-h the 

 particles of sand are afterwards driven, and having 

 attained the summit, fall down the declivity, which 

 they continually enlarge. At the base another sund- 



Fig. 65. — A Village buried under i^aud Dunes. 



hill commences its inclined plane, and the same 

 action of the wind effects a similar transference of 

 the sand to a third hill. The materials of each dune 

 are thus driven from one drift to another; so that 

 they are continually being destroyed, and as con- 



