On the road to Down from Keston a mound has been thrown across a considerable valley, but even against this mound there is no appearance of even a small pool of water having collected after the heaviest rains.

The water all percolates straight downwards.

Ascertain average depth of wells, inclination of strata, and springs.

Does the water from this country crop out in springs in Holmsdale or in the valley of the Thames?
Examine the fine springs in Holmsdale.
The valleys on this platform sloping northward, but exceedingly even, generally run north and south; their sides near the summits generally become suddenly more abrupt, and are fringed with narrow strips, or, as they are here called, "shaws" of wood, sometimes merely by hedgerows run wild.

The sudden steepness may generally be perceived, as just before ascending to Cudham Wood, and at Green Hill, where one of the lanes crosses these valleys.