68 THE WONDERS OF GEOLOGY. Lect 



are undergoing slow but perpetual destruction by the com- 

 bined effects of atmospheric agency, and of running water, 

 the coasts, cliffs, and shores, are exposed to destruction 

 from the action of the waves, and the encroachments of the 

 sea. When the land presents a high and rocky coast, the 

 waves, by their incessant action, undermine the cliffs, which 

 at length fall down, and cover the shore with their ruins. 

 The softer parts of the strata, as the chalk, limestone, marl, 

 clay, &c. are rapidly disintegrated and washed away; while 

 the more solid materials are broken, and rounded, by the 

 continual agitation of the water, and give rise to those 

 accumulations of shingle and sand which skirt the base of 

 the sea-cliffs, and serve, in some situations, to protect the 

 land from further encroachments. But when the cliffs are 

 entirely composed of soft substances, their destruction is 

 very rapid, unless artificial means be employed for their 

 protection ; which, however, in many instances are wholly 

 ineffectual. 



The encroachments of the ocean upon the land effected 

 by this agency, often give rise to sudden and extensive 

 inundations, and the destruction of whole tracts of country. 

 Along the Sussex, coast the inroads of the sea have been 

 noticed in the earliest historical records ; and the site of 

 the ancient town of Brighton has been entirely swept away, 

 the sands, and the waves, now occupying the spot where the 

 first settlers on these shores fixed their habitations.* On 

 low and sandy coasts, the waves drive the loose and lighter 

 materials towards the land ; and the drifted sand, becoming 

 dry at the reflux of the tide, is carried by the wind inland, 

 and in some situations is accumulated in such quantities as 



* In my "Fossils of the South Downs," and " Geology of the South- 

 East of England," will be found some interesting historical notices of 

 the destruction of the Sussex coast by the inroads of the sea. These 

 have been copied almost verbatim into several geological work*, 

 without acknowledgment or reference. 



