The situation was, however, by no means agreeable. After nightfall the Americans planted two howitzers and a 6-pounder on the top of a high building close to the western side of the plaza. Taylor's mortar had been carried to Worth during the day, and after sunset it began to fire now and then on the cathedral, where tons of gunpowder were stored. The citadel undertook to reply, but the mortar, planted behind the stone wall of the cemetery, was not likely to be struck, and a single one of its bombs might conceivably have blown the Mexican army to pieces. In fact so might a shot from Taylor's 24-pound howitzers, which delivered two shells effectively after dark. On the southern side of the river, opposite the town, the Fifth Infantry had planted one of the El Soldado guns at the third work on Federation ridge, where it could at least have proved annoying. The horses of the cavalry were in the way. The garrison of the citadel could not promptly coöperate with the troops in town, for it had sealed up the exit. Ampudia's defensive policy discouraged the soldiers, for even though some of them flanked the retiring Americans on Wednesday afternoon, they were not permitted to reoccupy the houses abandoned by Taylor, and still less to attack the redoubts. Despondency was general; some of the leading officers urged surrender; and Ampudia, it was reported, keeping the choicest corps near his person, shut himself up in the cathedral until a shell dropped near it, and then fled to a private house.[12.10] [NEGOTIATIONS] Naturally, then, early on Thursday morning one of his aides carried to the American general a proposition to give up the city, and retire with the troops and military material. Taylor replied with a demand for unconditional surrender, and insisted upon having an answer by noon. Instead of complying Ampudia sent a request for a personal interview. The result was a joint commission. Vexatious negotiations followed. The tedious and wily methods of Mexican diplomacy were thoroughly tried; but at length an ultimatum from Taylor's representatives ended the affair, and the terms of capitulation were signed. These provided that the citadel should be given up immediately, that within a week the Mexican troops with their arms, accoutrements and six field pieces should retire--without giving their parole not to fight again--beyond the line of Rinconada Pass, Linares and San Fernando de Presas, that before this evacuation of Monterey the town should be occupied by the Americans for hospital and storage purposes only, and that for eight weeks--"or until the orders or instructions of the respective governments can be received"--the Americans would not cross the specified line.[12.11]