SAND-HILLS. 6 I 5 



and when the wind assists the sea, and heaps up the water, the sight is 

 grand in the extreme. On the coast of Schleswig, at Hallingen, the sea has 

 washed away a whole cluster of islands, and now the waves cause. tremendous 

 inundations. About every six years, on the average, a great flood happens 

 for such trifles as a high tide are of no account In 1362 and in 1834 

 terrible destruction was wrought ; the coffins and bodies were washed out of 

 the graves. Piles of debris are then washed up, and sand and gravel accu- 

 mulates for a time till again carried away. 



Travellers to France will notice the " dunes," or sandhills of Calais, as 

 the train winds its way to Boulogne. We find that whenever the shore is 

 flat the shingle and sand are blown inwards and form " dunes," and the sand 

 is distributed far inland, checking all vegetation, and altering the features of 

 the country. The wearing away of rocks by the water, the continual under- 



Fig. 702. The Dunes 



mining of them by the waves, and sometimes the disengagement of great 

 blocks weighing many tons all these effects of the sea tend to alter the 

 appearance of the land. We may observe the denudation in many places 

 along the coast the caves, holes, and tunnels eaten out by the water. In 

 Norway the "Fiords" are very remarkable. They were formed by the 

 upheaval of the land, and tell us of the glaciers which once filled them up. 

 Thus by ice and water the solid land is ground down and eaten away hourly, 

 daily, and for countless centuries, changing the place of the hard rock into 

 a standing water, and the flintstone into a springing well. 



We must now plunge beneath the waves, never fearing the rough 

 surface ; we shall find all smooth and quiet at the bottom of the sea, 



. 

 THE BOTTOM OF THE SEA. 



What can we tell about the bottom of the sea to which no man has 



