290 Proceedings of the Royal Physical Society. 



edge of the Carse, the remains of the Roman Portus ad 

 Valium, 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 than 

 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 the 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." \ 



* Stewart's " Caledonia Komana," p. 177. 



f It is a curious fact, that during the oscillations which accompanied the 

 deposition of tho carboniferous rocks in central Scotland, a great inequality ap- 



