I am afraid I should never get on if I entered on the subject of fortification; but I may say in two words, that the structures of the Moors, so long in advance of artillery, have borne unscathed its brunt. At the Gibelfar of Malaga, Tarifa, Alcala, &c., are to be found rudiments of advanced works, of glacis and counterscarp, with a regular system of flanking walls. At Estepona, I observed angular fortification, the link between the old system and the new. There are walls for the purpose of resisting artillery, twenty-five feet high and as many thick, on which the guns must have been mounted _en barbette_. Their Spanish pupils anticipated Vauban.[40] This region has been fertile in destructive inventions. Gunpowder was first used for mining by the Spaniards at Baza, about 1480, superseding the old practice detailed in Timour’s Memoirs, which was, to set fire to the beams which supported the roof of the mine after it had been carried under the walls.[41] It was in the Straits of Gibraltar, before Ceuta, that artillery was first introduced afloat, in 1518, by Don Gonzalo Zarto, in the service of Don John of Portugal. It was at the last siege of Gibraltar that shells were thrown horizontally, and that red-hot shot were first used. But antiquity also furnishes her share of discoveries. It is not travelling too far to set down as belonging to the same list, the sling of the Balearic Islands, and the leaden bullets which, as Ælian tells us, the Romans obtained from Morocco. The battering-ram was first used at Cadiz, during the short struggle between the Phœnician colonists and their unnatural brothers of Carthage.[42] The Iberian sword borrowed by Rome, may also be recorded in presence of the first Roman colony--Carteia.