[125] The two letters may be found in full in the appendices to Belmas, vol. ii. Having received such an answer Moncey had only to set to work as fast as possible: his engineer-in-chief, General Lacoste, after making a thorough survey of the defences, pronounced in favour of choosing two fronts of attack, both starting on the Monte Torrero, and directed the one against the fort of San José and the other against that of the Pillar. These projecting works would have to be carried before any attempt could be made against the inner _enceinte_ of the town. At the same time, Lacoste ordered a third attack, which he did not propose to press home, to be made on the castle of the Aljafferia, on the west side of the town. It was only intended to distract the attention of the Spaniards from the points of real danger. On the further bank of the Ebro, Gazan’s division was directed to move forward again, and to entrench itself across all the three roads, which issue from the suburb, and lead respectively to Lerida, Jaca, and Monzon. He was not to attack, but merely to blockade the northern exits of Saragossa. Communications with him were established by means of a bridge of boats and pontoons laid above the town. Gazan succeeded in shortening the front which he had to protect against sorties by letting the water of the Ebro into the low-lying fields along its banks, where it caused inundations on each of his flanks. On the twenty-third the preliminary works of the siege began, approaches and covered ways being constructed leading down from the Monte Torrero to the spots from which Lacoste intended to commence the first parallels of the two attacks on the Pillar and San José. Preparations of a similar sort were commenced for the false attack on the left, opposite the Aljafferia. Six days were occupied in these works, and in the bringing up of the heavy artillery, destined to arm the siege-batteries, from Tudela. The guns had to come by road, as the Spaniards had destroyed all the barges on the Canal of Aragon, and blown up many of its locks. It was not till some time later that the French succeeded in reopening the navigation, by replacing the sluice-gates and building large punts and floats for the carriage of guns or munitions.