Vi^n. VI. — View on Mitcham Common. 



CHAPTER II. 



GEOLOGY OF MY GARDEN. 



WHEN I first entered upon the land of my garden, I could not walk 

 across it ; it was a kind of peaty bog. However, I lowered the 

 central brook, made a second stream, parallel with the river, and another 

 crossing the garden at right angles. The ground in many places 

 has been turned over, as we find occasionally brick piers. In some 

 parts of the ground are beds of gravel of an inferior character, in 

 other parts gravel full of water is found immediately below the surface. 

 Below this is a layer of coarse flints, constituting a drift bed running 

 from Croydon. Some of these ■'°„o °=>ju'"^°. • o 

 flints contain fossils, as though ■" ° o^ "« o' 

 they were washed out of the fig. 19. 



chalk (fig. 18). The whole is Q G>Q^ 

 covered with a poor exhausted \^3 Q^ y-P 

 peat, which rhododendrons de- ^ v-^ 



Fig. 18.— Flint cast of , , . , , FiG- 20.— Reigale Sand, 



Cidaria. test, and whlCh not many plants enlarged lo diam. 



like. Within the memory of many of my friends, the place was used 

 for bleaching and printing grounds, such as now exist on a similar 

 river between Amiens and the chalk downs on the road to Paris. On 

 the southern part of the garden a bed of sand exists, the last bed of 

 the Lower Tertiary series. This sand is extremely minute (fig. 19), 

 much finer than the Lower Green-sand at Reigate (fig. 20), a bed 

 below the chalk, of both which I have given figures. Notwithstanding 

 the fineness of the grains, the bed as a whole can be tunnelled, 

 as is actually the case in the cave on Mr. Watney's property.. 



