There are three elevations on the ridge, one in the centre, and one at each extremity. That in the centre is the highest; and here is the signal station, from which works are carried straight down to the beach at the ragged staff. The upper part of the Rock is like a roof, and down it, like forked lightning, runs a zig-zag wall. Below this stony thatching there is a story or two of precipices; the line of defence drops over them and on the works, which shut in the town on the south, and which consist of a curtain-bastion and ditch. In the rear of this wall (the zig-zag) there are the remains of a still more ancient one. A great amount of labour has been expended upon this almost inaccessible height. These zig-zag, or flanking lines, are naturally assumed to be modern, and the wall goes by the name of Charles V., who restored the fortification below; but the loop-holes are for cross-bows. The diagonal steps at the landing-places, the materials and the coating, as well as the whole aspect, show them to be Moorish. Heterodox as this opinion was held when I first broached it, it was not impugned after two inspections by the officers best qualified to pronounce on such a matter. On the north, too, all our defences are restorations of the Moorish works: even in the galleries they have been our forerunners. Their open works were in advance of ours, and a staircase is cut out through the Rock down to the beach. In fact, save in what is requisite for the application of gunpowder, or what is superfluous for defence, the Moors had rendered Gibraltar what it is to-day. They have even left us structures of the greatest service, as resisting the effects of gunpowder, and such as we are able neither to rival nor to imitate. On the great lines, in consequence of the many changes which have taken place, the original work has been displaced, or covered up, and especially so along the sea-wall; but, ascend to the signal-post,--crawl out on the face of the Rock to the north,--examine even yet Europa Point--Rozier Bay, and everywhere you find the Moor. It is impossible to move about at Gibraltar, without having the old tower in sight, and it is difficult to take one’s eyes off it when it is so. No aspiring lines, no graceful sweeps, no columned terraces exert their fascination, nor is it ruin and dilapidation that speak to the heart. The building is plain in its aspect, mathematical in its forms, clean in its outlines, with a sturdy and stubborn middle-aged air, without a shade of fancy or of wildness. Nevertheless, the eye is drawn to it, and then your thoughts are fixed on it--and they are so, precisely because you cannot tell why.