The effects of the rise of the tide are sometimes very disastrous, 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 débris are then washed up, and sand and gravel accumulates 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 undermining 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.
Fig. 702.—The Dunes.
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 ever reached living, and from which we have no information? We can lay our telegraph or telephone lines beneath the waves, and far from the restless waves in those quiet depths where no billows can reach. What treasures must lie hidden at the bottom of the sea! The treasures, the gold and silver, the merchandize, the wealth of centuries. The sailor lies sleeping there
... “Serene and safe
From tempest and from billow;
The storms that high above him chafe