346 THE BOTTOM OF THE SEA. 



Danish settlements. The cause of this cooling is, 

 very probably, a general elevation of the whole 

 eastern coast, whilst the western coast has subsided. 

 The elevation has had a double effect: it has 

 e'iminished the temperature while increasing the 

 altitude of the country ; it has compelled the warm 

 waters of the Gulf Stream to flow more to the east — a 

 result which has contributed enormously to diminish 

 the temperature of the country. We shall not be 

 astonished at this, if we consider the enormous 

 influence exercised on climate by marine currents. 



The Netherlands, as M. Elie de Beaumont has 

 shown, are subsiding gradually. Koman construc- 

 tions may there be seen surrounded by water, 

 having long since been passed by the coast-line. 

 Peat-beds, at one time important, have been buried 

 beneath the sea during the historic period. As the 

 oceanic waters, filtering through a porous soil, con- 

 tinued to rise, the Lakes of Haarlem were gradually 

 enlarged, until at the end of the seventeenth century 

 they united to form an inland sea. 



It is all in vain that men have attempted to raise 

 powerful dams against the encroachment of the sea. 

 The dams sink slowly w^ith the soil on which they 

 rest, and there is no doubt that, in a more or less 

 distant future, the barrier wliich they oppose will be 

 insufficient to protect the low-lying plains of Holland. 



