Meanwhile, Eugene was actively prosecuting the siege of Lille. Trenches were opened on the 22d, and a heavy fire was opened from eighty pieces of cannon. On the following night, an outwork, called the Chapel of St Magdalene, was stormed and taken. The second parallel was soon completed, and some farther outworks carried; and the whole battering guns having at length been mounted, a breach was effected in the salient angle of one of the horn-works, and on the same night a lodgement was effected. A vigorous sortie, on the 10th September, hardly retarded the progress of the operations, and a sap was made under the covered way. Marlborough, who visited the besiegers' lines on the 18th, however, expressed some displeasure at the slow progress of the siege; and in consequence, on the 20th, another assault was hazarded. It was most obstinately resisted, but at length the assailants overcame all opposition and bursting in, carried a demi-bastion and several adjoining works, though with a loss of two thousand men. Great as this loss was, it was not so severe as that of one officer who fell; for Eugene himself, transported with ardour, had taken part in the assault, and was seriously wounded. This grievous casualty not only gave the utmost distress to Marlborough, but immensely augmented his labours; for it threw upon him at once the direction of the siege, and the command of the covering army. Every morning at break of day he was on horseback to observe Vendome's army; and if all was quiet in front, he rode to the lines and directed the siege in person till evening, when he again returned to the camp of the covering force. By thus in a manner doubling himself, this great man succeeded in preventing any serious inconvenience being experienced even from so great a catastrophe as Eugene's wound, and he infused such vigour into the operations of the siege, that, on the 23d September, great part of the tenaillons were broken, with a large portion of the covered way. At the same time the ammunition of the garrison began to fail so much in consequence of the constant fire they had kept up for above a month, that Marshal Boufflers sent intimation to Vendome, that unless a supply of that necessary article was speedily obtained, he should be obliged to surrender.[34]