From beneath the south escarpment of the North Downs the chalk marl and greenaand formations crop out. They occupy the valley which extends at the foot of that escarpment all through the county, and east of Reigate is called Holmesdalo; but as the formations extend southward from the chalk they rise into hills, among which are Leith Hill (993 feet, the highest point in the county, and indeed in this part of England), Hoimbury and Coneyhurat Hills, and Hind Head Common, on the Hampshire border, 923 feet high. This range of hills presents a bold escarpment towards the valley on the south, and is broken by two considerable depressions, one near Reigate, by which the Mole passes through, and another between Hurtwood Common and linscombe, through which a feeder of the Way passes; and by some minor interruptions. Beds of chest occur in the chalk marl near Reigate, and fire-stone is dug in the same formation at Merstham. The high grounds of these formations are almost entirely waste. On Hind Head Common occurs that remarkable hollow, the 'Devil's Punch-bowl,' round which the Portsmouth road winds for nearly a mile. The rest of the county, comprehending the whole of the southern border, except a very small part west of Ilaslemere, is occupied by the Weal] clay and iron-sand formations. Tho latter only just appears at the south-eastern corner of the county. The Weald clay occupies the broad valley at the foot of the greensand hills, and in some place. forms the lower part of the south side of the bills.
Hydrograpie and Coarartraieat?ons.—The county is included in the basin of the Thames, except throe very small portions ; two south of the greansand bills, which aro drained by streams flowing into the Arun, and a third iu the south-east corner of the county, which belongs to the basin of the Medway. The Thames which forms the northern boundary, is navigable throughout for small craft, and London Bridge for sea-borne vessels. Those of its tributaries which belong to Surrey are the Bourn Brook, the Wey, .the Mole, the Hog's Mill River, the stream whichjoins above Putney, and the Wandlo. The Bourn Brook rises near Bagahot, and flows by Chobharn and Addlestone into the Thames below Chertsey, sending off one branch into the Wey ; it receives a stream from Virginia Water in Windsor Great Park : its whole length is about 14 miles.
The Wey rises near Alton in Hampshire, and flows north-east about 9 miles to the border of Surrey, which it enters not far from Farnham.
Thence it flows by Farnham to Tilton', where it receives, on the right bank, a considerable stream from Woolmer Forest in Hamp shire, and runs eastward to Godalming, where it becomes navigable.
From Godalming it flows by Guildford and Woking into the Thames at Weybridge. The Wey has several tributaries in the county. The whole length of the Wey is about 11 miles, for about 18 miles of which it is navigable. The Mole rises in the northern part of the county of Sussex. It enters Surrey at Charlwood, passes Henley,
Kennerley Bridge, Dorking, Leatherhead, and Cobham, and flows into the Thames at East Molesey, opposite Hampton Court. Its whole course is about 42 miles. It is not navigable in any part. The Hoes Mill River rises in a copious spring in the village of Ewell, and flows north-west 7 miles into the Thames at Kingston. It is not navigable, but turns several mills. The stream which joins the Thames near Putney rises at the foot of Banstead Downs near Cheam, and flows northward by Richmond Park, and Barnes, where it turns east and joins the Thames half a mile above Putney Bridge ; its length is almost 10 miles: it is not navigable. The Wandle rises near Croydon, flows by Carshalton, Mitcham, and Wandsworth, into the Thames : its course is only 11 miles, and it is not navigable, but it works nnmerous The canals are the Grand Surrey Canal, the Wey and Arun Canal, and the Basingstoke Canal. The Grand Surrey Canal is cut from the Thames at Rotherhithe, about a mile and a half to the neighbour hood of Deptford, iu Kent, and then turning west is carried two miles and a half farther to Camberwell. There is an extensive basin in the part of the canal near the Thames. The Wey and Arun Canal, sometimes called the Surrey and Sussex Canal, commences in the river Wcy near Shalford, between Guildford and Godalming, and runs south by east (II miles) into Sussex, where it joins the Arun naviga tion near Billinghurst. The Basingstoke Canal commences in the river Wey, about 3 miles above its junction with the Thames, and runs south-west nearly 12 miles to Frimley, near the border of the county ; it than turns south and runs above three miles to near Alder 'heft, where it enters Hampshire.
The principal roads in the county are those which lead from the metropolis to the south-cast, south, and south-west. The Dover road, as far as New Cross, near Deptford, is in this county. Tho Brighton road runs south from Southwark through Brixton, Croydon, and Merstham. Here it divides, one branch running through Reigate, the other running over Red Hill and through Healey. The two branches reunite near Henley, and run across Lowfleld Heath to Cawley in Sussex. The most frequented Portsmouth road leaves the metropolis at Hyde Park Corner, and enters the county over Putney Bridge, but formerly the more frequented road was through Newington and Wandsworth. The two roads unite beyond Putney, and run south west by Kingston, Guildford, and Mousehill. The Winchester and Southampton road branches from this to the right at Guildford, and runs west along the llog'a Back to Farnham. The Salisbury and Exeter road enters the county across the Thames at Staines, and runs just within the north-western border and parallel to it through Egbam and Bagshot. There are numerous branch and cross roads.