AN ENGLISH SIIIRE. 183 



Buachy, would swell slowly upward till it reached a 

 height of two or three thousand feet at the Surrey 

 border, and would fall again gradually towards the 

 Thames valley at London. On the southern side of the 

 Downs this is pretty much what we now get, the Tertiary 

 strata being preserved in the district near Chichester ; 

 though farther east, around Newhaven and Beachy 

 Head, the sea has encroached upon the chalk so as to cut 

 out the great white cliffs which bound the view every- 

 where along the shore from Brighton to Eastbourne. In 

 the central portion of the boss, however, almost all the 

 highest elevated part has been denuded by ice or water 

 action. Between the North and South Downs, where 

 we ought to find the mountain ridge, we find instead the 

 valley of the Weald. Here the chalk has been quite 

 worn away, giving rise to the keep escarpment on the 

 northern side of the South Downs, seen from the Devil's 

 Dyke, so that at the foot of the sudden descent we get 

 the Weald clay exposed ; while in the very centre of the 

 upheaved tract the clay itself has been cut through, and 

 the Hastings sand appears upon the surface. Moreover, 

 the sand, being upraised by the central force, stands 

 higher than the clay on either side, which forms the 

 trough of the Weald ; and thus the forest ridge, which 

 abuts upon the sea in the cliffs of Hastings Castle, seems to 

 lie above the clay, under which, however, it really glides 

 on either side. I need hardly add that this rough 

 diagrammatic description is only meant as a general 

 indication of the facts, and that it considerably simplifies 

 the real geological changes probably involved in the 

 sculpture of Sussex. Nevertheless, I beUeve it pretty 



