The Rock, we must add, is divided into two unequal parts by a ridge extending from north to south. The western section is a gradual slope, broken up with precipices; but the eastern, which looks out upon the blue Mediterranean, and the northern, facing the Spanish batteries, are both very steep, and, in fact, inaccessible. At the foot of the north-west slope, and surrounded by irregular fortifications, lies the town, which communicates with the isthmus by a long, narrow causeway, strongly bristling with defensive works. These, and the causeway itself, are over-looked by the guns mounted in the King’s, Queen’s, and Prince’s lines; ramparts excavated out of the solid rock, and practicable only to birds of prey. At different heights, up to the very crest, batteries are planted so as to present to an enemy a peculiarly grim and forbidding aspect. The Old Mole, to the west of the Grand Battery, joined with the above lines to pour a tremendous cross-fire on the causeway and Neutral Ground. So great an annoyance did this battery prove to the besiegers, that, by way of distinction, they named it the Devil’s Tongue; and the entrance into the garrison, with its batteries here, there, and everywhere, and its cannons and mortars on the causeway and Old Mole, suggested to them the picturesque title of the Mouth of Fire. All along the sea-line were stout bastions, joined by curtains, which were mounted with great guns and howitzers, and supplied with casemates for 1000 men. These sufficiently defended the town; which was protected also by a rocky shoal, stretching along the front far into the Bay, and preventing the approach of large ships. From the south bastion a curtain stretched up the base of the hill, and terminated the fortifications of the town at an inaccessible precipice. Here was placed the South-port gate, with a dry ditch in front of it, a covered way, and glacis. Above this gate, on the rugged slope of the hill, and connected with the curtain, was a large bastion, pointing its guns at the Bay. Further up, an ancient Moorish wall ran along to the ridge of the rock, in the front of which a curtain, with loop-holes and redans, built in the reign and christened by the name of Charles V., extended to the summit. Between these two walls, the Moorish and the Emperor’s, stood the Signal-House, whence, on a clear bright day, the guard could command an unimpeded view of the Mediterranean, and discern even the shining waters of the Atlantic over the Spanish mountains. “Signals,” says Drinkwater, “formerly were made at this post on the appearance of topsail vessels from east and west, but soon after the commencement of the late war we discovered that the Spanish cruisers were more frequently informed of the approach of our friends by our signals than by their own. The signals were therefore discontinued during the siege, but resumed after the general peace of 1783.”