Alvarez and his garrison would behave according to the accepted rules of siegecraft, and yield when their situation became hopeless. But in dealing with Spanish garrisons the rules of military logic did not always act. Alvarez essayed the impossible, and held out behind his defective defences for four months after Monjuich fell. The loss of men and time that he thereby inflicted on the French was certainly no less than that which would have been suffered if the besiegers had begun with the Mercadal, and worked upwards by incessant street fighting towards the forts on the height. But it is hard to say that Verdier erred: he did not know his adversary, and he did know, from his experiences at Saragossa, what street fighting meant. [31] See Belmas, iii. 516. It may be added that Verdier’s views were accepted by the engineer-general, Sanson, who had been specially sent from France by the Emperor, to give his opinion on the best mode of procedure. The document which Verdier, Sanson, and Taviel (the commanding artillery officer of the 7th Corps) sent to Paris, to justify their choice of the upper point of attack, lays stress mainly on the impossibility of advancing from the Mercadal under the fire of the upper forts[32]. But there were other reasons for selecting Monjuich as the point of attack. It lay far nearer to the road to France and the central siege-dépôts beside Sarria and the Pont Mayor. The approaches would be over highly defensible ground where, if a disaster occurred, the defeated assailant could easily recover himself and oppose a strong front to the enemy. The shortness of the front was suitable for an army of the moderate strength of 14,000 men, which had to deal with a fortress whose perimeter, allowing for outlying forts and inaccessible precipices, was some six miles. Moreover, the ground in front of the Mercadal had the serious inconvenience of being liable to inundation; summer spates on the Ter and Oña are rare, but occur from time to time; and there was the bare chance that when the trenches had been opened all might be swept away by the rivers[33]. [32] See their letter in Appendix V to Belmas’s account of the siege. [33] Note, ibid., ii. p. 502.