The cité was then completely surrounded within bowshot distance. No sortie could be of any serious use to the besieged; for Secondinus had established posts supported by intrenchments around the ramparts. Seeing the success of his last efforts, the Frank chiefs began to place more confidence in the Latin engineer, and were obedient to his orders. Then Secondinus resumed his attack on the north front, and began four mining galleries, making use of that which he had been forced to abandon. Three were led under the square tower of the north-west corner[16] (Fig. 33). The besieged soon heard the strokes of the miners' pickaxes, and attempted a countermine, starting from the tower itself, at A; but Clodoald was no longer there to direct the workmen, who, wishing to repeat the manoeuvre previously adopted, dug too deep, crossed the enemy's galleries underneath them, and had no clear perception what direction their sapping should take. The sounds they heard were diffused, and seemed to issue from several points; and, in fact, the Franks were working in more than one direction, and, as Secondinus ordered, immediately under the foundation; sometimes they were digging in the sand, and all noise ceased; sometimes they would meet with rock, and then the blows of the pioneers again became audible. [Illustration: FIG. 33.] The countermine gallery, therefore, was winding about, and only weakened the basis on which the tower rested; and four days after the commencement of the work, it was supported only by dry props, greased and smeared with pitch. These being set on fire, the tower fell in, bringing down with it a large piece of the north wall. Anticipating this result, King Gondomar, who, after Clodoald's death, took the command in the cité, had ordered an interior retrenchment to be raised, with a strong wooden tower in the middle of the curve, projectile engines being placed behind. He had sufficient time to complete these works after the fall of the tower; for the breach was scarcely practicable, and was stoutly defended. The Franks were two days in getting possession of it and occupying the corner of the cité in front of the retrenchment, not without having lost two or three hundred men. Secondinus interdicted the advance of the troops, who were eager to storm the retrenchment and take it by main force; and this time he was listened to. He had timber and mantelets brought, and gave orders for the erection, on the very ruins of the angle, of a tower of green wood, which he took care to protect with woollen blankets and fresh hides. The engines of the defenders did not cease to discharge large stones at the workmen, which greatly hindered them and killed many; but the Franks had acquired confidence, and worked incessantly night and day with enthusiastic ardour.