38 
Mr. Willi an Phillips on the 
mination at Copt Point consists of the blue marie, which in some 
parts may be from 40 to 50 feet thick. 
The run of this cliff is not quite parallel with that of the chalk 
cliffs between the signal-house and Dover. The dip of the sand- 
stone lying in the green sand is about the same as that of the chalk, 
as it appears on the surface of those cliffs. 
Although from the similarity of this bed of marie to that which 
is observed in other places to lie between the chalk and green sand, 
there can be no doubt that it passes under the chalk, yet it is not 
easy to discover it so interposed. 
The chalk cliff turns southward towards Folkstone near the sig- 
nal-house, presenting a ridge which slopes rapidly ; so that the 
chalk is not seen in situ quite so far down as the nearest of the 
three Martello towers. Below that place, all is ruin for a consi- 
derable part of the way to Copt Point ; the colour of the chalk 
being lost by insensible degrees in the blue marie, and both to- 
gether occupy the descent to the shore for a short distance. Be- 
tween the second Martello tower and the shore, the descent chiefly 
consists of the blue marie, w r hich continues to Copt Point ; and it 
can scarcely be doubted that the high ground between the shore 
east of the Martello towers, and the Canterbury road, and perhaps 
still further west, consists mainly of the blue marie, which is visible 
soon after that road has branched from the road to Dover, in a field 
on the right, from which the alluvium has been removed in search 
of flints for mending the road. It also appears in a field at the foot 
of some high chalk ground behind a small farm house near the 
second of the Martello towers ; where a spring of pure water issues 
from beneath the chalk, and running over the marie makes its way 
down the descent, consisting chiefly of chalk ruin, into the sea. 
The perishable nature of the marie seems to have been the chief 
