562 



breadth, .at the foot of the escarpment of this range, extending from 

 Godstone by Merstham, Reigate, and through the county into Hamp- 

 shire, defines the geographical range and extent of the firestone. At 

 Merstham it is well developed. " The church stands upon a mound, 

 or hillock, of this rock, from the base of which a spring gushes out 

 immediately beneath the firestone." The gait forms a corresponding 

 narrow depression along its whole length, and is seen to emerge on 

 the surface from under the firestone, forming a belt of stiff soil, which 

 may be traced by Bletchingly, Merstham, and Reigate. The remain- 

 ing part of this division forms a small portion of the lowermost group 

 of the chalk formation, that important and extensive series of arena- 

 ceous strata, for which the term lower greensand is employed, which 

 rise into a range of hills, running parallel with the southern escarp- 

 ment of the North Downs. The district yielding fuller's earth hitherto 

 explored, is about two miles in length from east to west, and a quarter 

 of a mile in breadth. The little village of Nutfield has long been 

 celebrated for this mineral, which has for centuries been dug in its 

 neighbourhood. 



The view from the summit of the chalk-hills to the north of Rei- 

 gate is as interesting to the geologist as to the lover of the picturesque, 

 for it presents a magnificent landscape, displaying the physical struc- 

 ture of the weald, and its varied and beautiful scenery. 



From the porous nature of the chalk-hills they are uniformly dry, 

 permitting the free passage of the rain-water ; so that there is almost 

 a total absence of surface-drainage. From the gait that forms the 

 foundation of the chalk-hills numerous springs and rivulets issue, 

 which unite and form the river Wandle. 



3. South-eastern Division. 



The south-eastern division has its northern boundary defined by the 

 road from Westerham, passing by Limpsfield, through Bletchingly, to 

 the railway at the Reigate junction, and thence by the Reading 

 and Reigate Railway to the Dorking station. The western boundary 

 is continued thence through Dorking, by the turnpike-road leading 

 towards Horsham ; the counties of Sussex and Kent respectively 

 forming the southern and eastern boundaries. The area is about one 

 hundred and nineteen square miles. 



With the exception of a narrow strip oi the lower greensand run- 

 ning along the northern boundary, the whole of this division is of the 

 wealden-clay formation. A stiff blue clay invariably appears, and 

 forms the subsoil of the district to its junction with the adjacent 



