GEOLOGY in reptilian bones and teeth, belonging to the extinct genera Iguanodon^ Hylceosaurus, Cetiosaurus, etc. During medieval times the ironstone was collected and smelted at many places along the outcrop of the Wadhurst Clay in Kent, as well as in the adjacent parts of Sussex and Surrey ; and this industry continued so long as the forests of the Weald were sufficiently extensive to yield a good supply of wood or charcoal for fuel. Traces of the old excavations and of the slag-heaps where the stone was smelted are still visible in many places, as for example on the rising ground between Tonbridge and Penshurst. The fine ironwork railings which were round St. Paul's in London until about thirty years ago were wrought at Lamberhurst on the Kentish border. In the year 1740 there were still four furnaces in Kent, but these had fallen into desuetude before 1788.^ Tunbridge Wells Sand. — This term is applied to the uppermost sub- division of the Hastings Beds, from the district where it is widely developed. The Tunbridge Wells Sand does not diffisr much from the Ashdown Sand in general character, its material varying from a fine loamy semicoherent sand, with intercalations of silt and mottled red clay, to a soft thick-bedded sandstone, often with seams of small pebbles in the upper part. In the latter condition it forms the picturesque rocks of Rusthall Common and High Rocks near Tunbridge Wells. This subdivision occupies the greater part of the tract covered by the Hastings Beds in Kent. It is occasionally sufficiently indurated to be quarried as a building stone, and sandpits are numerous in its softer beds. The soils derived from it are sometimes too ' light ' for profitable tillage, and such tracts remain as uncultivated moorland or woodland ; but more frequently there is a sufficient admixture of loam and clay to produce fertile arable land at its outcrop. It rarely contains fossils other than fragmentary traces of plants. Like the Ashdown Sand, it is generally a water-bearing formation, the more porous sandy beds being the source of numerous springs; but the water is liable to be slightly chalybeate, as in the well-known springs at Tunbridge Wells. The Hastings Beds were evidently formed as sandbanks in a lake or estuary by currents of considerable strength, with intervals of stiller water in which the intercalated muds and clays were deposited. The sands are very generally ' false-bedded,' i.e. the original stratification of the com- ponent layers has not been horizontal, but has accorded with the slope of the more or less steeply inclined banks into which the sediments were driven. Consequently it is not surprising to find that although the total thickness of the series in southern Kent and Sussex, where the greater part of the material was deposited, exceeds 600-700 feet, it has been proved by the deep borings to thin away very rapidly northward and north-eastward, and is entirely absent in the northern part of the county. The river-system which transported the sediments forming the Hastings Beds has usually been supposed to have flowed from a land ' ' Geology of the Weald,' p. 331. 7
