Four eighteen-pounders had followed the army from Almeida, three twenty-four pound howitzers were furnished by the field-artillery, and the battering train used by Hill at Almaraz, had passed the bridge of Alcantara the 11th. These were the means of offence, but the strength of the forts had been under-rated; they contained eight hundred men, and it was said that thirteen convents and twenty-two colleges had been destroyed in their construction. San Vincente, so called from the large convent it enclosed, was the key-fort. Situated on a perpendicular cliff overhanging the Tormes, and irregular in form, but well flanked, it was separated by a deep ravine from the other forts, which were called St. Cajetano and La Merced. These were also on high ground, smaller than San Vincente, and of a square form, but with bomb-proofs, and deep ditches, having perpendicular scarps and counterscarps. In the night of the 17th colonel Burgoyne, the engineer directing the siege, commenced a battery, for eight guns, at the distance of two hundred and fifty yards from the main wall of Vincente, and as the ruins of the destroyed convents rendered it impossible to excavate, earth was brought from a distance; but the moon was up, the night short, the enemy’s fire of musketry heavy, the workmen of the sixth division were inexperienced, and at day-break the battery was still imperfect. Meanwhile an attempt had been made to attach the miner secretly to the counterscarp, and when the vigilance of a trained dog baffled this design, the enemy’s picquet was driven in, and the attempt openly made, yet it was rendered vain by a plunging fire from the top of the convent. On the 18th eight hundred Germans, placed in the ruins, mastered all the enemy’s fire save that from loop-holes, and colonel May, who directed the artillery service, then placed two field-pieces on a neighbouring convent, called San Bernardo, overlooking the fort, however these guns could not silence the French artillery. In the night, the first battery was armed, covering for two field-pieces as a counter-battery was raised a little to its right, and a second breaching battery for two howitzers, was constructed on the Cajetano side of the ravine. At day-break on the 19th seven guns opened, and at nine o’clock the wall of the convent was cut away to the level of the counterscarp. The second breaching battery, which saw lower down the scarp, then commenced its fire; but the iron howitzers proved unmeet battering ordnance, and the enemy’s musketry being entirely directed on this point, because the first battery, to save ammunition, had ceased firing, brought down a captain and more than twenty gunners. The howitzers did not injure the wall, ammunition was scarce, and as the enemy could easily cut off the breach in the night, the fire ceased.