28 THEORY OF THE EA11TH. 



the sea also throws up sand upon them, and thus 

 contributes to their increase ; there are created, 

 as it were, provinces, and even entire kingdoms, 

 which usually become the most fertile, and speedily 

 the richest, in the world, if their rulers permit 

 human industry to exert itself in peace. 



Formation of Downs.* 



The effects which the sea produces, without 

 the co-operation of rivers, are much less benefi- 

 cial. When the coast is low, and the bottom 

 sandy, the waves push the sand toward the shore, 

 where, at every reflux of the tide, it becomes par- 

 tially dried ; and the wind, which almost always 

 blows from the sea, drifts it upon the beach. 

 Thus are formed those hillocks of sand, named 

 Downs, which, if the industry of man does not 

 fix them by suitable plants, move slowly, but in- 

 variably, toward the interior of the country, and 

 overwhelm fields and dwellings, because the 

 same wind that raises the sand of the beach up- 

 on the down, throws that of its summit in the op- 

 posite direction from the sea. When the nature 

 of the sand, and that of the water which is raised 

 with it, are such as to form a durable cement, 

 the shells and bones, thrown upon the beach, be- 

 come incrusted with it. Pieces of wood, trunks 



*NoteG. 



