The combined action of the fleet—præmissa classe—as well as the history of the previous campaigns, exclude any position west of the Tay; and if Dealgan Ross is evidently not the place, from the limited size of the camp, Ardoch is equally objectionable, from there being no hill near which answers the description of ‘Mons Granpius.’ The expression ‘transisse æstuaria’ in the plural, in Agricola’s speech, places it north of the Firth of Tay. The position at Urie involves the improbability that he marched for several days parallel to the range of the so-called Grampians, if his route was by Strathmore, and there are no camps to indicate a march nearer the coast before the battle was fought. The remains of this ‘vallum’ or rampart between the Isla and the Tay are still among the most remarkable Roman works in Scotland, and are known by the name of the Cleaven Dyke. It seems to have been the work of the same general who constructed the great camp at Ardoch, for, in connection with the latter, was a small work of an octagonal shape, with many ramparts, and the only other specimen the author has observed of a similar work is at the east end of the Cleaven Dyke. Footnote 54: See for an elaborate description of this wall Mr. Collingwood Bruce’s exhaustive work, _The Roman Wall, a Description of the Mural Barrier of the North of England_, third edition, 1867. The main authority for Hadrian’s work in Britain is Ælius Spartianus (181), who says, ‘Ergo conversis regio more militibus, Britanniam petiit: in qua multa correxit, murumque per octaginta millia passuum primus duxit, qui Barbaros Romanosque divideret.’—(_De Hadr._ 11.) CHAPTER II. THE ROMAN PROVINCE IN SCOTLAND. [Sidenote: Ptolemy’s description of North Britain.]