1809-1S42] DOWN 35 



The flat summit-land is covered with a bed of stiff red Letter 12 

 clay, from a few feet in thickness to as much, I believe, 

 as twenty feet : this [bed], though lying immediately on the 

 chalk, and abounding with great, irregularly shaped, unrolled 

 flints, often with the colour and appearance of huge bones, 

 which were originally embedded in the chalk, contains not 

 a particle of carbonate of lime. This bed of red clay lies 

 on a very irregular surface, and often descends into deep 

 round wells, the origin of which has been explained by Lyell. 

 In these cavities are patches of sand like sea-sand, and like 

 the sand which alternates with the great beds of small pebbles 

 derived from the wear-and-tear of chalk-flints, which form 

 Keston, Hayes and Addington Commons. Near Down a 

 rounded chalk-flint is a rarity, though some few do occur ; 

 and I have not yet seen a stone of distant origin, which 

 makes a difference — at least to geological eyes — in the very 

 aspect of the country, compared with all the northern counties. 



The chalk-flints decay externally, which, according to 

 Berzelius {Edin. Neiv Phil. Journal, late number), is owing to 

 the flints containing a small proportion of alkali ; but, besides 

 this external decay, the whole body is affected by exposure of 

 a few years, so that they will not break with clean faces for 

 building. 



This bed of red clay, which renders the country very 

 slippery in the winter months from October to April, does 

 not cover the sides of the valleys ; these, when ploughed, 

 show the white chalk, which tint shades away lower in the 

 valley, as insensibly as a colour laid on by a painter's brush. 



Nearly all the land is ploughed, and is often left fallow, 

 which gives the country a naked red look, or not unfrequently 

 white, from a covering of chalk laid on by the farmers. 

 Nobody seems at all aware on what principle fresh chalk 

 laid on land abounding with lime does it any good. This, 

 however, is said to have been the practice of the country 

 ever since the period of the Romans, and at present the many 

 white pits on the hill sides, which so frequently afford a 

 picturesque contrast with the overhanging yew trees, are all 

 quarried for this purpose. 



The number of different kinds of bushes in the hedgerows, 

 entwined by traveller's joy and the bryonies, is conspicuous 

 compared with the hedges of the northern counties. 



