224 Tides Illustrative of Geological Phenomena. 



bay, so as to describe a bend, which the seamen of this 

 country call a Hook. Sandy Hook, in the Bay of New York, 

 is of this character. Such, also, are the Hook of Cape Cod 

 and the Hook of Holland. The direction of the Hook is in- 

 variably that of the current. 



The coasts of Europe offer numerous examples of these 

 various forms of alluvial deposits. Lines of narrow banks, 

 like those on the coasts of New Jersey and the Carolinas, 

 have been described by M. Elie de Beaumont, on the shores 

 of France, as, for instance, near Dieppe, and in the depart- 

 ment of Finisterre. On the other hand, the Bay of Biscay 

 offers in its sands (which are carried by the winds into the 

 interior, and formed into dunes) a striking example of the 

 bay-deposits. But it is the Netherlands that merit the 

 greatest attention. Sand-banks are rare on the north-west 

 coasts of France ; but no sooner do we quit the Channel than 

 we find them scattered throughout the North Sea. Holland 

 itself is in a great measure formed of alluvial sand. Now, 

 these deposits are formed precisely on the spot most favour- 

 able to the formation of alluvial deposits, namely, where the 

 tidal current, having passed through the Channel, enters the 

 vast basin of the North Sea. The deposition of sand-banks 

 in the North Sea is favoured, moreover, by the meeting of 

 two tides on the coast of Jutland (one coming from the Chan- 

 nel, and the other passing round the island of Great Britain), 

 forming what the hydrographers call a tide-node, which im- 

 plies, generally, a continual eddy, which is more favourable 

 than anything to the formation of sand-banks. 



Considered in their general connection, the alluvial depo- 

 sits of a continent should be looked upon as the product of a 

 series of currents and eddies alternating with each other, the 

 final result of which is to transport, in the direction of the 

 flood, the moveable materials which the waves and atmo- 

 spheric agents have detached from the coast-beaches. This 

 is particularly striking on the coast of the United States. 

 The alluvial deposits form, at first, only a narrow line on the 

 coast of Florida ; this line enlarges insensibly on the coasts 

 of the Carolinas, Virginia, and New Jersey ; it becomes 

 wider on the coast of Massachusetts, and finally attains the 



