MODEEtf GEOLOGICAL CHANGES. 347 



in the year 1665, twenty-two tenements had been ingulfed 

 by the waters, but one hundred and thirteen still remained, 

 which were destroyed by the great storm of 1705.* The 

 waste still continues ; the road called the Marine Parade has 

 repeatedly been narrowed ; a battery formerly stood at the 

 bottom of the New Steine, the site of which is now swept 

 away. Proceeding westward along the Sussex coast, we 

 find various instances of land having been ingulfed ; several 

 large churches, built in the immediate vicinity of the sea 

 are extremely disproportioned, in size and endowment, 

 to the scanty population by which they are surrounded. 

 We have already alluded to the mode by which the cliffs of 

 the Isle of Wight are sapped, and landslips produced. The 

 promontories and headlands on the south side of the island 

 are composed of strata appertaining to the cretaceous period. 

 Alum Bay and Whitecliff Bay are hollowed out of the ter- 

 tiary strata (fig. 252), and the bays of Sandown and Compton 

 of the equally yielding beds of clay and sand belonging to 

 the wealden, and neocomian rocks. 



In investigating the southern coast, we find the same 

 conditions prevailing ; the bays are scooped out of softer 

 deposits, while the harder rocks, which have withstood the 

 action of the waves, constitute the promontories and head- 

 lands. The latter are in a continual course of abrasion, their 

 destruction being more rapid where the substratum consists 

 of clay. Such is the case in the Isle of Wight, and the 

 peninsulas of Portland and Purbeck. The great landslip of 

 December 24th, 1839, which occurred on the coast between 

 Lyme and Axminster, was produced under similar circum- 

 stances, the upper beds consisting of strata belonging to the 

 chalk and greensand formations ; the lower being composed 

 of clay appertaining to the lias. The springs traversing the 

 greensand had previously loosened the upper beds, and, by 

 moistening the clay, produced frequent falls, forming a kind 

 of undercliff. On this occasion, the season had been unusu- 

 ally wet, and the upper strata having become saturated with 

 moisture, the clays had been rendered slippery, and the 

 entire mass was set in motion, the whole of the beds above 

 the lias, comprising masses of chalk, chert, and greensand, 



* Dr. Mantell's Geology of Sussex. 



