On the platforms of the three great northern towers 3 3 In the casemated batteries of these towers 6 On the earthwork in front of the northern boulevard 2 On the northern boulevard 1 2 On the boulevards B, C, H, I, K 5 5 On the cavalier commanding the bridge 1 2 Reserve in the abbey and the castle 4 8 -- -- Totals 14 28 -- -- On the 10th of September the besiegers began a cavalier in form of a horseshoe, three hundred paces from the boulevard, E, towards the north-east, to rake its gorge at A (Fig. 53). This cavalier was armed with two bombards and a spirole. Northwards, on the side of the road, a second cavalier, B, was also provided with two bombards. Next was commenced an earthwork, running obliquely with traverses, to reach from this cavalier in a south-west direction as far as the edge of the plateau near the defenders' intrenchment C, D. The great boulevard, E, of the defence was armed with a bombard and two culverins, and two other culverins flanked the intrenchment C, D. On the morning of the 17th of September, the four bombards of the besiegers sent into the boulevard stone balls two hundred pounds weight, which very much damaged the gorge, and about noon dismounted the bombard and one of the culverins. The besieged had answered their fire as well as they could, both from the boulevard and the two great towers G, H. But it was only the balls of the bombard mounted on the platform of the tower H, that reached the cavalier A. Those of the tower G only rolled as far as the slope of the cavalier B. The governor might have mounted other bombards on the boulevard E; but he was afraid of losing the pieces, and preferred reserving them for the defence at close quarters. On the 18th the besieger had terminated his earthwork as far as the point I, and there he brought up a veuglaire to dismount the flank culverin C. At this point some men were lost on both sides; for the besiegers sent among those engaged in the works large balls of stone and leaden bullets, fired from the bombards of the tower G, and from small cannon. [Illustration: FIG. 53.]