The guns of the works were so poorly mounted, that but few could be used at all; and these, on account of the construction of the fort, could not reach the ships, though anchored close by the walls.

"Only five of their guns," says Napier, "placed in a flanking battery, were well served, and never missed; but they were pointed too high, and damaged our spars and rigging only." The stone was of so poor a quality, says the narrative of Colonel Matuszewiez, that the walls fired upon presented on the exterior a shattered appearance, but they were nowhere seriously injured.

In the words of Napier, "_they were not breached, and a determined enemy might have remained secure under the breastworks, or in the numerous casemates, without suffering much loss_." The accidental explosion of a magazine within the fort, containing six thousand casks of powder, laid in ruins a space of sixty thousand square yards, opened a large breach in the walls of the fortifications, partially destroyed the prisons, and killed and wounded a thousand men of the garrison.

This frightful disaster, says the French account, hastened the triumph of the fleet.

The prisoners and malefactors, thus released from confinement, rushed upon the garrison at the same time with the mountaineers, who had besieged the place on the land side.