282 
TIIIO (iRUl.OfllST. 
with or merges iiito great drifts of angular flint-gravel, bnt in the area 
we arc traversing the brick-earth is very pure and free from any con- 
siderable quantity of fragmentary flints. 
It must be borne in mind that the })lain over which we have been 
walking, although at the foot of the lofty chalk downs, is still at a 
Li<,ni. 21. — Chiilk Downs, near Folkestone. 
high level above the sea, and forms the continuation of that high 
ground of the Gault and Lower Greensand at Folkestone, which con- 
stitutes the "West Cliff, and is cut ofi" from the East Clifi'or Copt Point 
by a valley from eighty to ninety feet deep, in which a considerable part 
of the old town is built. In this valley several springs of beautifully 
clear water break out, the most noticeable being that at the " Bull- 
dog steps," which even in the driest and hottest seasons pours forth 
in undiminished flow. 
At the south-eastern comer of the West Cliff, under the Battery, 
lying immediately on the upper beds of the Lower Greensand, which 
are of loose disintegrated sand, is the Pleistocene ossiferous deposit, 
from one to nine feet thick, to which we alluded at page 125. It con- 
sists of flint- jiebbles, boulders, and fragments of ferruginous sand- 
stone, intermixed with loamy sand and surmounted by calcareous 
marl. This bed extends along the face of the clifl" for a distance of 
three hundred and twenty feet, following the irregularities of the 
