Here is an original in design and substance, a work surpassing those of the Romans in strength, and equalling those of the Egyptians in durability. As the zig-zag lines have been attributed to the Spaniards, so on high authority is a much more recent date[31] than that which I here assign to them given to the Moorish fort and tower; but supposing them to be of no earlier date than the fourteenth century, they would still illustrate a style of architecture which the Moors introduced, and which, like language, is lost in the mists of antiquity. They are now busy in demolishing the works that connected the Moorish fort with the harbour. Whilst tracing the old wall from the former to the latter, I came upon a large arch, and satisfied myself that this had been an entrance to an inner harbour. On subsequent reference to James’s History of Gibraltar, I find that this was well known in his time. During these researches, in which I spent a month, I had not the aid that is generally obtained from the observations of others. I often attempted to look into books, but was always constrained to throw them aside, and return to the writings on the wall. What manner of men were these Moors?--the ruins suggested the question, and books furnished no answer. On the sea-side, Gibraltar is open to the fire of vessels, and would have been captured on one occasion, but for the dissensions between the combined forces. We have retained it only by a new invention, _red-hot shot_. The land-entrance is defended as follows: first, the isthmus round the north face of the Rock is dug out and filled with water, and between this basin, called the Inundation, and the Bay, a causeway only is left, which can be swept away at once by the enormous guns from the overhanging caverns. Behind the Inundation, is the glacis, elaborately mined; and behind the ditch there is a curtain, mounting eighteen or twenty guns, which fills up the gap between the Rock and the works on the port. As you advance along the narrow causeway between the Inundation and the Bay, you have this curtain in front. To the right stretches out into the water, a long low mole called the “Devil’s Tongue,” and between it and the curtain, there is tier upon tier of embrasures over the Port and the Port entrance. To the left of the curtain, the sharp engineering lines scale the rocks, and link the chain of defence to the Moorish Tower. Thence the cliffs sweep away round to the left, parallel to the causeway, along which you are advancing. The Rock is shaved into lines for musketry, or pierced with port-holes, which stretch away in rows far and high. On the crest of the first precipice, batteries and guns are scattered. You see them again on the loftiest summit of the Rock, so that as you approach, you pass over ground swept with metal, and through successive centres of converging fire. This is by the Spaniards called “Bocca del Fuego.” At each step, from all around, above, below, from Merlon, rock, and