260 
On the Agricultural Geology of the Weald. 
land unenclosed, but far less than on Ashdown Forest. The soils 
of both areas are much alike. 
The fourth great sandy area is that along the borders of Kent 
and Sussex, south-east of Tunbridge Wells, separated by a band 
of clay country from the light land, also of considerable extent, 
north of Cranbrook. The greater part of this area, however, ij 
very different in character from the Ashdown and Heathfield 
districts. The land, though still light, is of much better quality. 
In the absence of analyses of rocks and soils from these different 
districts, there appears no sufficient reason for such variations. It 
is true, the sands belong to different horizons of the series ; those 
of Heathfield and Ashdown Forest are the " Ashdown sands,"" 
as are also the comparatively sterile lands of Fairlight, near 
Hastings. The light land around Cranbrook is almost entirely 
composed of Tunbridge Wells sand — the uppermost member of 
the Hastings Beds. But there is a great similarity between thesQ 
beds, and no one, even when most minutely acquainted with the 
country, could possibly tell from inspecting a quarry or sand-pit 
to which horizon the bed exposed therein should be referred. 
There may be, and often are, quite local characters which are of 
service to a geologist in mapping the country ; but I am not 
aware of any well-defined character by which the Tunbridge 
Wells sands can, as a whole, be distinguished from the Ashdown. 
sands. Possibly the chief cause of the difference is height above 
the sea. The sterility of the Sussex sands has been ascribed to 
the iron they contain ; but I doubt whether the most sterile soils, 
are more ferruginous than others. 
The character which most distinguishes the Wealdcn sands 
and sandstones is their extreme fineness. We rarely meet witk 
sands as coarse and sharp as those of the Lower Greensand. 
The coarser sands generally occur as rock-beds, such as are Avell 
known in the neighbourhood of Tunbridge Wells. This fine 
state of division makes it less easy for water to pass through the 
sands, and they, therefore, have, when wet, some of the charac- 
ters of clay. Rushes very frequently grow in abundance over land 
in which analysis would show but a small quantity of clay ; but 
there is often more clayey matter, not making the land in any 
sense stiff, but only a sandy loam, and this, together with the 
fineness of the sand, gives the land over it a very wet appear- 
ance. It is a complaint that sheep are fed with difficulty on 
such land, which has, therefore, many of the disadvantages of 
clay without its strength. 
The Tunbridge Wells sand contains some subordinate beds 
of clay, the chief of which is most fully developed around I'last 
Grinstead, and is called Grinstead Clay. There it resembles 
the Wadhurst Clay in character. Further east, however, what 
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