Again taking the Wall as our guide, we will pursue our course westward. For the greater part of the way along the high ground, the Wall is in a sufficiently good state of preservation to make it a varied and interesting study; it not unfrequently exhibits five, six, and even seven courses of facing-stones. The Northumbrian lakes also lend a charm to the scene. Though appearing in native simplicity and rude grandeur, they will not on that account be less appreciated by men of taste. The Vallum is generally very boldly developed, and runs for several miles in the valley below, completely commanded by the hill on which the Wall stands, as is shewn in the section, Plate IV. This fact is surely fatal to the theory of its having been erected to withstand the brunt of a northern foe. It would have been impolitic to allow the enemy to occupy these heights even as a post of observation. It is true, that the Vallum is occasionally commanded by the rising ground on the south: opposite Sewingshields it is so, and opposite Hot-bank, a little to the west of where we now are, it is overlooked on both sides. This difficulty is not a very formidable one. The engineer of the Barrier has drawn the Vallum chiefly in straight lines from one point to another, and has not thought it necessary to guard with excessive jealousy every little rising ground to the south; he never, however, departs from his course to go round the north of a hill, as he does to go round the south of that one near Halton-chesters. The cases, moreover, in which the Vallum is exposed to observation from the south, are very few. Horsley’s own testimony upon this point is decided. He writes— It must be owned, that the southern prospect of Hadrian’s work, and the defence on that side, is generally better than on the north; whereas the northern prospect and defence have been principally, or only taken care of in the Wall of Severus.[111] [Sidenote: RAPISHAW-GAP.] After passing a mile-castle we come to a depression in the ridge of basalt, that places us opposite the west end of Broomlee-lough; the crag on the west side of this slack is called Cuddy’s-crag. A little farther on, we reach a more extensive pass, called Rapishaw-gap; a road passes through it under the same circumstances as that through Busy-gap, a little above the bottom of the valley. The traveller may here with advantage go to the north of the Wall, in order to examine the geological character of the cliffs he has passed; they are seen ‘to rise in rude and pillared majesty.’