It was finally agreed to attack the bastion of Trinidad, because the counterguard there was unfinished, and the bastion could be battered from the Picurina. The first parallel was therefore to embrace that fort, the San Roque and the eastern front, so as to enable the counter-batteries to destroy the armaments of the southern fronts, which bore against the Picurina hill. The Picurina was to be stormed, and from thence the Trinidad and the next bastion, called the Santa Maria, were to be breached. The guns were then to be turned against the connecting curtain, known to be of weak masonry, and to open a third breach, whereby a storming party might turn any retrenchments behind the other breaches. In this way the inundation could be avoided. A French deserter declared, and truly, that the ditch was eighteen feet deep at the Trinidad, yet Wellington was so confident that he resolved to storm the place there without blowing in the counterscarp. The battering train was of fifty-two pieces, including sixteen twenty-four-pound howitzers for throwing Shrapnel-shells; but this species of missile, much talked of at the time, was little prized by Lord Wellington, who had detected its insufficiency, save with large guns and as a common shell; and partly to avoid expense, partly from a dislike to injure the inhabitants, neither in this, nor in any former siege did he use mortars. Here indeed he could not have brought them up, for the peasantry, and even the ordenança, employed to move the battering train, although well paid, deserted. Of nine hundred gunners present three hundred were British, the rest Portuguese; there were one hundred and fifty sappers, volunteers from the third division, unskilled, yet of signal bravery. The engineer’s park was established behind the heights of St. Michael which faced the Picurina, and in the night of the 17th, eighteen hundred men broke ground one hundred and sixty yards from that fort. A tempest stifled the sound of the pickaxes, and a communication four thousand feet long, with a parallel of six hundred yards, three feet deep and three feet six inches wide, was opened without hindrance; but when day broke the fort was reinforced, and a sharp musketry, interspersed with discharges from some field-pieces and aided by heavy guns from the body of the place, was directed on the trenches. In the night of the 18th two batteries were traced, the parallel prolonged, and the previous works improved; but the garrison raised the parapets of the Picurina, lined the top of the covered way with sand-bags, and planted musketeers to gall the men in the trenches.