There is another piece of Roman work in the neighbourhood of Newport Gate, which is a piece of wall built with ashlar and binding courses of tile. It is known as the Mint Wall. But perhaps the most interesting of all the Roman remains in Britain is the Roman Wall, which reaches across the narrow part of the island in Northumberland and Cumberland, commencing at Wallsend, on the Tyne, running through Newcastle and Carlisle, and terminating at Bowness, in Cumberland. A most interesting and fully illustrated account of this wall has been given to the world by the Rev. J. Collingwood Bruce, from whose work we have (by permission) copied the two illustrations on p. 22. [Illustration: NEWPORT GATE, LINCOLN. (_From a Photograph by Skill, Lincoln._)] Arguments have been brought forward by some antiquaries to show that the wall and the vallum by which it is accompanied belong to two different periods; but Dr. Bruce contends that they are both to be considered as forming part of the great engineering work of Hadrian. It consists of a stone wall, or _murus_, and a wall of earth, or _vallum_. These two run always near together, but not always parallel. The vallum is likewise rather the shorter, terminating at Newcastle on the east, and at Drumburgh, about three miles from Bowness, the western extremity of the wall. "The most striking feature in the plan, both of the murus and the vallum, is the determinate manner in which they pursue their straightforward course. The vallum makes fewer deviations from a right line than the stone wall; but as the wall traverses higher ground, this remarkable tendency is more easily detected in it than in the other. Shooting over the country, in its onward course, it only swerves from a straight line to take in its route the boldest elevations. So far from declining a hill, it uniformly selects one. "For nineteen miles out of Newcastle the road to Carlisle runs upon the foundations of the wall, and during the summer months its dusty surface contrasts well with the surrounding verdure. Often will the traveller, after attaining some of the steep acclivities of his path, observe the road stretching for miles in an undeviating course to the east and the west of him, resembling, as Hutton expresses it, a white ribbon on a green ground. But if it never moves from a right line, except to occupy the highest points, it never fails to seize them as they occur, no matter how often it is compelled, with this view, to change its direction. It never bends in a curve, but always at an angle. Hence, along the craggy precipices between Sewingshields and Thirlwall, it is obliged to pursue a remarkably zigzag course; for it takes in its range, with the utmost pertinacity, every projecting rock." [Illustration: TRANSVERSE SECTION OF THE ROMAN WALL.]