Towards evening, however, the traverse was completed, though several parties of engineers had been destroyed in the task, and preparations were made to erect a gallery upon it. In spite of the constant severe fire from the ramparts and bastions--in spite of the stones and missiles hurled upon them--the engineers persisted in their work, and laboured with such resolution and assiduity, that, in less than an hour, a gallery, eight feet high and twelve wide, was put together. The sides were formed of double planks, the intervals being filled up with earth, and the pointed roof was covered externally with raw hides, so as to prevent it from being set on fire. A critical juncture had now arrived for the besieged. Had the breach been sufficiently large, the assault would inevitably have taken place, for Bourbon was fully prepared; but not only was the aperture insufficient, but it could be seen that a rear rampart had been erected, which would have to be stormed when the outer wall was carried. Once more, therefore, the assault had to be deferred, and in consequence of this delay all the works which it had cost so many lives to execute were thrown away. Heavy cannon, placed on the bastions commanding this angle of the walls, were brought to bear upon the gallery, and the damage done by the shot enabled the besieged to set fire to it by means of burning barrels of pitch, which they hurled upon it. The whole fabric was soon in flames, and the conflagration, which was witnessed by the whole of the Imperial army, produced a very striking effect, as it illuminated all the ramparts, towers, and structures in its vicinity. Bourbon had thus the mortification of seeing the work, on which so much labour had been expended, utterly destroyed. As soon as the gallery was consumed, and the blackened beams had fallen into the moat, the energetic commanders of the garrison ordered ladders to be brought, and a large party of men descended for the purpose of destroying the traverse. Before they could accomplish this, they were attacked by a strong detachment of Spanish infantry, and a desperate conflict took place. The Spaniards were driven back with great loss, but, as they were speedily reinforced, the besiegers were compelled to abandon the work and remount the walls. Shortly after this occurrence, a council of war was held by Renzo da Ceri and Chabot de Brion in a large hall in the episcopal palace. Ever since the commencement of the siege this splendid structure had been abandoned by the bishop, who had taken up his abode in a less exposed part of the city, and the palace was now occupied by troops. All the principal officers of the garrison were present, and Renzo announced to the meeting that it would be necessary to demolish the palace in whieh they stood, as well as the venerable church of Saint Cannot adjoining it, lest the besiegers should obtain possession of them.