158 THE OCEAN. 





composed of a sandy clay, wliicli tlie rain alone suffices to wash away 

 and this gives rise to a talus of masses of solid conglomerate detached 

 from the upper layers, which thus protects the cliffs from the fury of 

 tlie waves. In the same way, on the sterile shores of Brittany, the 

 blocks of granite, cracked in all directions, and converted into shingle 

 which the sea carries away and returns again, maintain intact during 

 centuries the walls of rocks of which they formerly made a part. 



The cliffs of Normandy, composed of materials much less hard 

 than those of the promontories of Brittany, are also more easily worn 

 away; still we must attribute their rapid erosion principally to the 

 coastal current which carries away the shingle accumulated at the 

 base of the rocks. The talus of fallen blocks constitutes at first a per- 

 fectly sufficient defence against the fury of the waves : but little by 

 little, the chalky part of the rock is dissolved and deposited here and 

 there on the mud-banks, while the masses of flint disengaged from 

 the substance of the stone, cease to present a sufficient resistance to 

 the waves, and are carried away into the neighbouring bays in im- 

 mense processions parallel to the shore. On the south coast of Eng- 

 land, the current of the coast is much less energetic, and the talus 

 can in consequence long resist the attacks of the sea. A few years 

 ago the waters undermined with a threatening rapidity the base of 

 the cliff which rises not far from Dover, on the western side, and 

 which the English have consecrated to Shakspeare, in remembrance 

 of the beautiful description which he has given of it in King Lear. 

 To preserve this historical promontory, the houses that it supports, 

 and the railroad which runs through it in a tunnel, they formed the 

 plan of blowing down the upper part. In the presence of an im- 

 mense crowd, assembled to see this new spectacle, they fired hun- 

 dreds of pounds of powder buried in a mine, and enormous masses of 

 rock fell with a crash from the top of the hill ; and now the force 

 of the waves is broken on their talus. Mr Beete Jukes thinks that 

 during 18 centuries this cliff and the neighbouring rocks have been 

 worn away by nearly 1 mile.* 



In the North Sea there is an island which by a singular mis- 

 apprehension was believed to have been consecrated to Freya, the 

 goddess of love and liberty, and whose ancient name of Halligland 

 (land with the inundated banks) has been transformed for foreigners 

 into that of Heligoland (holy land). The island, composed entirely 

 of mottled stone, formerly surrounded by cretaceous beds, presents to 

 the sea all round a cliff about 200 feet high, worn away at the base 



♦ School Manual of Geology, p. 89. 



