ALTERATIONS OF COAST LINE. 



391 



and agitated by the blast, rises and beats against them with inconceivable fury, the 

 continual action of the water slowly consumes their masses. The perpetual play of waves, 

 tides, and currents gradually wastes away the base of towering cliffs ; and when this pro- 

 cess of undermining has reached a certain extent, the upper parts, deprived of support, 

 fall down, and, after their destruction, a fresh attack commences upon the coast line. 

 This demolition proceeds at a varying rate, according to the hardness or yielding nature 

 of the material that forms the shore. The granite rocks endure for centuries the wear 

 and tear of the ocean with but little loss, while the limestone and chalk cliffs are more 

 easily subdued. The chalk cliff at Dover has suffered large and repeated losses since 

 Shakespeare wrote the notice of it in King Lear : 



" The crows and choughs that wing the midway air 

 Show scarce so gross as beetles. Half-way down 

 Hangs one that gathers samphire ; dreadful trade ! 

 Methinks he seems no bigger than his head : 

 The fishermen that walk upon the beach 

 Appear like mice ; and yon tall anchoring bark, 

 Diminished to her boat her boat, a buoy 

 Almost too small for sight. The murmuring surge, 

 That on th' unnumber'd idle pebbles chafes, 

 Cannot be heard so high : I'll look no more, 

 Lest my brain turn, and the deficient sight 

 Topple down headlong." 



Immense fragments have frequently fallen from this cliff, owing to the undermining of 

 its base, some of which have shaken the neighbouring town as by an earthquake, and the 

 height of the cliff has been considerably abridged by these detachments, the slope of the 

 hill being towards the land. The slipping down of large masses of steep coast is a phe- 

 nomenon due to the same cause the loosening of the foundations by the incessant 



Uiidercliff, Isle of Wight. 



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