The guns established by the besiegers in their new batteries among the ruins of the town made such good practice upon the front of the citadel that Reille thought it worth while on the twenty-eighth to summon the Governor to surrender. O’Daly made a becoming answer, to the effect that his defences were still intact and that he was prepared to continue his resistance. To cut him off from his communication with the sea, the only side from which he could expect help, Reille now began to build batteries along the water-front of the town, which commanded the landing-places below the citadel. The English ships proved unable to subdue these new guns, and their power to help O’Daly was seriously diminished. It was only under cover of the darkness that they could send boats to land men or stores for the citadel. On the thirtieth they tried to take off the sick and wounded, who were now growing very numerous in the place: but the shore-batteries having hit the headmost boat, the rest drew off and abandoned the attempt. The prospects of the garrison had grown most gloomy. Meanwhile the Trinity fort had been perpetually battered for ten days, and the hole in the great frontal tower was growing larger. It can hardly be called a breach, as owing to the impossibility of searching the lower courses of the wall by the plunging fire from the Puig-Rom, the lowest edge of the gap was forty feet from the ground. The part of the tower which had been opened was the upper section of a lofty bomb-proof casemate, which composed its ground story. Lord Cochrane built up, with the débris that fell inwards, and with hammocks filled with earth and sand, new walls inside the bomb proof, cutting off the hole from the interior of the tower: thus enemies entering at the gap would find that they had only penetrated into the upper part of a sort of cellar. The ingenious captain also set a long slide or shoot of greased planks just under the lip of the hole, so that any one stepping in would be precipitated thirty feet into the bottom of the casemate. But the mere sight of this mantrap, as he called it, proved enough for the enemy, who never pushed the attack into it.