I 1 SECTION FROM LONDON TO BRIGHTON. 363 



The Weald clay, containing beds of fresh-water limestone. 

 appears at Horley common ; and while in the commence- 

 ment of his journey the roads were made of broken chalk- 

 flints, and at Reigate of oherty-sandstone, the materials 

 here chiefly employed are the bluish-grey calcareous rock 

 of the Weald. At Crawley, sand and sandstone appear, 

 and the road is constructed of grit and limestone, containing 

 liuviatile shells, bones, and plants. Crossing Tilgate 

 Forest and Ilcnulcross. over a succession of elevated ridges 

 of sandstone, and through clay valleys, produced by the 

 alternations of the strata, he descends from the sandstone 

 ridge at Bolney, near Cuckheld. and again journeys along a 

 district of Weald clay with fresh-water limestone. Green- 

 sand, like that of Reigate, reappears at Hiekstead, and is 

 succeeded by a tract of Gait; and tin ally, entering a valley 

 of Chalk-marl, he reaches a dehle in the South Downs, 

 through which the road winds its way to Brighton : the 

 traveller having in the course of his journey passed from 

 one chalk range to the other, and crossed over the inter- 

 vening area formed by the delta oi the Wealden. 



3. London and Brighton railway section. — A simi- 

 lar section is displayed along the line of railway from 

 London to Brighton. Leaving the station at London- 

 bridge, the tertiary clays with their characteristic fossils, are 

 seen from beyond Deptford, by Xew Cross, Sydenham, &c. ; 

 and approaching Croydon, beds oi gravel appear, with inter- 

 spersions of olive-green sand. The valley beyond Crovdon. 

 along the side of which the railway proceeds, is a thick bed 

 of gravel resting on the chalk. Beyond the station called 

 Stoats'-nest, is a fine section of the chalk with Hint, and 

 the North Downs are traversed by a long tunnel carried 

 through the solid chalk, and emerging near Merstham, 

 where the firestone and marl rise to the surface. The sands 

 and clays of the chalk are passed at the Eed Hill, and God- 

 stone stations and the Wealden clays appear at Horley, and 



