Nothing can less resemble our regular fortifications than the fort of Gallipoli, (before which we soon after passed,) and the other castles of the Dardanelles, which ought to render Constantinople the most impregnable place in the world (from the sea.) The forts are large buildings of a dazzling white colour, perforated with port-holes, similar to those belonging to a ship of war, and mounted with old guns, the greater portion of which are without carriages, and served, ordinarily, by a single artillery-man, assisted in time of war by three or four peasants. In the present century, however, these batteries have shown their prowess, and against our own countrymen too. During the month of February 1807, the British government, justly irritated at the increasing influence that the French ambassador, Count Sebastiani, was obtaining at the Ottoman court, despatched Admiral Sir John Duckworth, in command of a squadron, with orders to bombard, if necessary, the Seraglio itself. Unfortunately, Sir John Duckworth's plan of acting was exactly contrary to what would have been our gallant Nelson's in the same position. After having passed without difficulty before the then disarmed castles of the Dardanelles, after having burned the Ottoman fleet off Gallipoli, while the crews were peaceably celebrating on shore the feast of Courban-Beiram, Sir John presented himself off Constantinople, and threatened to bombard that city, should the Sultan refuse to accept the conditions he offered, at the same time he allowed his Imperial Highness two days to consider the terms; Nelson would have allowed as many hours only. The folly of Admiral Duckworth's conduct fully shown in the sequel, for, at the conclusion of the forty-eight hours, the approaches to Stamboul and Galata were bristling--thanks to the delay accorded, and to the exertions of the French ambassador--with twelve hundred pieces of cannon; while, at the same time, orders having been sent to the castles of the Dardanelles to mount their batteries, the British squadron was hemmed in on all sides, as if by enchantment. The besieged now became the aggressors, and there soon remained to Admiral Duckworth no other resource than to weigh anchor and get away as fast as possible, which he accordingly did. The batteries of the Dardanelles were now, however, prepared for him. A most destructive fire was opened upon the ill-fated fleet: two corvettes were sunk off Gallipoli; the Admiral's flag-ship, the Royal George, lost her mainmast; a huge marble ball, weighing eight hundred pounds, swept away a quantity of hands from the lower deck of the Standard, while many officers and seamen wore severely wounded. It must be here observed, that the batteries of the Dardanelles owed much of the murderous effect of their cannonading to the skill of eight French engineer officers, whom Count Sebastiani, profiting by the delay accorded by Admiral Duckworth to the Sultan, had despatched to the castles.