30 PROCEEDINGS COTTESWOLD CLUB I90I 
oscillations of the land in the south-west occurred as 
given in this paper, and have corresponded with those 
in the north-west, which are easier of interpretation. 
There is still one question of great interest which I may 
well touch upon, and that is the geological age of these 
buried forests. Mr. Pengelly has shown that the insula- 
tion of St. Michael’s Mount took place before the Christian 
era. He says “ Nineteen centuries ago it (the Mount) 
possessed a safe harbour, so that its insulation must have 
been effected long before. It was at one time unques- 
tionably ‘a hoar rock in a wood,’ but in all probability it | 
had ceased to be so long before any language now known 
to scholars was spoken in the district. Prior to its insu- 
lation was the era of the growth of the forests now sub- 
merged along our entire seaboard.” 
Again at Sea Mills on the Avon, below Bristol, there 
exist the remains of a very interesting Roman dock. These 
I examined on August Ist, 1888, and made the following 
entry in my note book—“ The masonry of lock gates is 
well preserved, and the stream of water running through 
has kept the apron clear of mud. These remains are 
extremely interesting, as showing that the type of dock was 
the same in Roman times as now; also as showing that 
no material change of level has taken place, for if the mud 
were cleared out and the walls repaired it might be used 
for a dock still. The tide washes in and out now.” 
The evidence in Cheshire and Lancashire on the shores 
of Liverpool Bay, points also to the conclusion that there 
has in that district been no material change of level since 
the Roman occupation; or, indeed, as estimated by me, 
from the bulk of blown sand overlying the Peat and Forest 
Bed on the Lancashire coast and its measured rate of accu- 
mulation, there has been no movement during the last 
1 Jour. of the Royal Institution of Cornwall, No. xiii., 1872. 
