Suddenly the men serving the gun in the casemate stopped their rapid yet deliberate work. A hostile shell had penetrated the 6-inch side armour almost under the casemate and had burst close to the lower part of the foremast. The shock well-nigh capsized the Sub, and almost caused the man at the ammunition hoist to drop the hundred-pound shell that he was in the act of transferring to the breech of the weapon. Suffocating fumes eddied through the ammunition hoist into the confined space. In the dim light men were gasping for breath, expecting every moment to find the magazine beneath their feet blown up. "Hoist out of action, sir," reported one of the men, as he threw the contents of a bucket of water down the choked tube. Although everything of a supposedly inflammable nature had been got rid of, the heat generated by the explosion had been sufficient to start a fire, and the seat of the conflagration was between the armoured floor of the casemate and the magazine below the water-line. "That's done it," ejaculated Dick dejectedly. It was not on account of the danger, for the men remained calmly within the casemate, trusting to the fire-party to extinguish the flames that were perilously close to the magazine. He was deploring the fact that the jamming of the ammunition hoist had deprived his gun of its supply of shells. The weapon was as much out of action as if the entire gun's crew had been annihilated. It seemed so humiliating to be inactive. "Number one 6-inch, why are you not firing?" inquired an officer in the conning-tower through one of the voice tubes. There was a tinge of anxiety in his voice. He had noticed the sudden cessation of fire from that particular weapon, and it looked ominous. "Ammunition hoist damaged, sir," replied the Sub. "Any casualties?" "No, sir." "Then stand by." Dick heard the whistle replaced in the tube as the officer completed his enquiries. Then hard-a-port the _Hammerer_ described a semicircle, in order to bring her as yet unengaged starboard battery into action. By this time the Turkish reply was but a feeble one. Pounded by the direct fire from the pre-Dreadnoughts; shattered by the long-range high-angle fire of the _Queen Elizabeth_ and the _Invincible_, the forts were little better than mounds of rubbish. Already the British warships had penetrated more than two miles up the formidable Straits, the mine-sweepers performing their difficult task with the utmost coolness and bravery. Night was coming on. All that could be done was to make sure of the complete reduction of the southernmost forts, and continue the sweeping operations as a prelude to a farther advance on the morrow.