We have seen that the northern salient had remained in the power of the Franks. Secondinus raised an _agger_ at this point, in front of the gate of the cité; and on the declivity of the plateau another _agger_ opposite and on the counterscarp of the fosse of the ramping wall (Fig. 27). The ridge of these works did not reach the level of the footway of the cité walls, but yet rose high enough to allow great stones to be discharged on the battlements by means of onagers, and to render the situation perilous to the defenders. The especial object of this was to occupy the besieged. Under shelter of these two earthworks, Secondinus had two mines commenced, one at the point A, the other at B, which, carried under the bottom of the dry ditches, were to penetrate beneath the walls. Clodoald, who had been rather severely wounded, was obliged to confide the superintendence of the defence to his lieutenants, who informed him of the besiegers' operations, and who believed that the Franks were going to raise timber works to command the walls, destroy the battlements, and throw bridges across. Nothing, however, favoured the supposition that such was the intention of the Franks, who limited themselves to furnishing the earthworks with screens to protect their engines. This apparent inactivity was a constant source of anxiety to Clodoald, who knew, through his spies, that the besiegers had received reinforcements. As he was unable to take the lead, he dared not direct his lieutenants to undertake any fresh sorties, and was obliged to content himself with recommending the most scrupulous vigilance. Trusting, moreover, to the solidity of the Roman walls and the rocky site of the plateau, he scarcely believed that mining could be rendered efficient; yet, in anticipation of such a contingency, he ordered that trusty men should be set to listen in the lower stories of the towers, and at the base of the walls opposite the face of attack; then he had platforms prepared behind the rampart to receive six machines, which discharged stones in abundance on the earthworks of the besiegers (Fig. 28). [Illustration: FIG. 28.] The Franks, on their side, were working vigorously at their two mining galleries, not without great difficulty, for they had at several points very hard rock to pierce. The excavated earth was heaped up within the earthwork, and could not be seen by the besieged. Till they reached the fosse the noise of the work could not be heard from the cité; but when the miners had arrived below the fosse, the men on guard in the town heard the sound of pickaxes dully reverberating through the night. Clodoald, informed of this, immediately gave orders to countermine, starting from the interior base of the rampart, and in the direction of the sound. On both sides, therefore, the miners were at work; but this did not prevent the projectile engines from being worked all day by both parties.