290 Proceedings of the Royal Physical Society. 
edge of the Carse, the remains of the Roman Portus ad 
Vallum, consisting of walls, houses, and docks, existed 
down to the last century, and that an anchor was dug up in 
the same locality.* 
*' This independent testimony corroborates in the most 
satisfactory manner the geological inference already stated 
in this paper. I visited the site of the ancient Camelon, 
and found it lying at the foot of the old coast line — a wavy 
line of bold bluffs, similar to but considerably higher tlian 
those of the Figgate Whins. It required no force of imagina- 
tion to picture the sea rising to the base of these cliffs, and 
ascending the valley of the Carron, with Roman galleys 
winding up the estuary, or anchored in the harbour of the 
long forsaken and forgotten Portus ad Vallum. 
Having shown that the coast at Leith has risen 
25 feet or so since the Roman invasion, it by no means 
follows that the coast along other portions of tbe Firth of 
Forth, and of the east of Scotland generally, has been 
elevated to the same amount. Nor is it necessary to the 
truth of the conclusions of this paper, that the west coast of 
Scotland — as for instance at the termination of the Wall of 
Antonine — should be proved to have experienced any eleva- 
tory movement at all. 
** Such movements are local in action and variable in 
amount, so that geologically there is no reason why the 
amount of rise may not have lessened towards the west, until 
in the Firth of Clyde it ceased altogether. No one can ex- 
amine the shores of our country without becoming convinced 
that they have been raised, not by equal and uniform eleva- 
tions, but by a general upheaval which varied greatly in 
amount in different localities, and was even interrupted by 
long intervals, during which the land appears to have re- 
mained stationary. Hence the raised beaches occur at dif- 
ferent levels above the present shore, and even the same 
line of upheaved littoral deposits may be proved to be actu- 
ally higher at one point than at another." t 
* Stewart's " Caledonia Komana," p. 177. 
t It is a curious fact, that during the oscillations which accompanied the 
deposition of the, carboniferous rocks in central Scotland, a great inequality ap- 
