560 



gravel, and sand, which are designated diluvium. The area occupied 

 by these deposits is designated the London Basin, and is of conside- 

 rable extent, occupying the whole of the north and north-western 

 division of the county, and varies from ten to twelve miles across from 

 north to south. 



Rivers. — The county is included in the basin of the Thames, ex- 

 cept three very small portions, two south of the greensand hills, which 

 are drained by streams flowing into the Arun, and a third in the south- 

 east corner of the county, which belongs to the basin of the Medway. 

 Independently of the river Thames, there are three principal rivers 

 (besides some smaller streams) which properly belong to Surrej', 

 namely : — 1st. The Wey, which rises near Alton, in Hampshire, and 

 enters the county at Farnhara, whence it flows with many bends, 

 receiving in its course several small streams, by Godalming to Guild- 

 ford, where it passes through the chalk ridge towards Weybridge, 

 below which it enters the Thames ; the whole length being alDout 

 forty-one miles, for about eighteen of which it is navigable. 2nd. 

 The Mole, which rises in the northern part of the county of Sussex, 

 near Hand Cross, and enters this county at various places on its south 

 and south-eastern confines: several of these branches congregate near 

 Gatwick, in this county ; and then, passing Horley, the united stream 

 runs northward to Kinnersly Bridge, receiving in its course a consi- 

 derable accession from various sources, till it reaches Betchworth and 

 Box Hill, at the base of which it penetrates through the chalk range 

 of the North Downs ; thence it passes by Leatherhead, and enters 

 the Thames at East Moulsey, opposite Hampton Court. Its whole 

 course may be estimated at forty-two miles. It is not navigable in 

 any part. 3rd. The Wandle, which rises near Croydon. It takes its 

 course westward by Beddington to Carshalton, and thence runs north- 

 ward by Mitcham and Merton, and passes on to Wandsworth, where 

 it unites with the Thames. Its course is only eleven miles, and is not 

 navigable. Besides the rivers which have been described, there is a 

 stream called Bourn Brook, which rises near Bagshot, and flows by 

 Chobham and Addlestone into the Thames below Chertsey. Its whole 

 length is about fourteen or fifteen miles. There is also a small stream 

 called Hogg's-mill river, which rises in a copious spring in the village 

 of Ewell, and flows north-west seven miles into the Thames at King- 

 ston. The stream which enters the Thames near Putney rises at the 

 foot of Banstead Downs, near Cheam. Its length is almost ten miles. 

 None of these are navigable. 



