In the night, though the works went on, rain again impeded progress, and the besiegers, failing to drain the lower parts of the parallel by cuts, made an artificial bottom of sand-bags. On the other hand the besieged, thinking the curtain adjoining the castle was the object of attack, threw up earth in front and removed the houses behind; they also made a covered communication from the Trinidad gate to the San Roque, to take this supposed attack in reverse; and as the labour of digging was great, hung up brown cloth which appeared like earth, by which ingenious expedient they passed unseen between those points. Vauban’s maxim, that a perfect investment is the first requisite in a siege, had been neglected to spare labour, yet the great master’s art was soon vindicated by his countryman. Phillipon, finding the right bank of the Guadiana free, made a battery in the night for three field-pieces, which at daylight raked the trenches, the shots sweeping the parallel destructively; the loss was great and would have been greater but for the soft ground, which prevented the touch and bound of the bullets. Orders were therefore sent to the fifth division, then at Campo Mayor, to invest the place on the other bank, but those troops were distant and misfortunes accumulated. Heavy rain filled the trenches, the Guadiana run the fixed bridge under water, sunk twelve pontoons, and broke the tackle of the flying bridges; the provisions of the army could not be brought over, the battering-guns and ammunition were still on the right bank, and the siege was on the point of being raised. In a few days however the river subsided, some Portuguese craft were brought up to form another flying bridge, the pontoons saved were employed as row-boats, and the communication thus secured for the rest of the siege. On the 23rd rain again filled the trenches, the works crumbled and the attack was entirely suspended. Next day the fifth division invested the place on the right bank, the weather cleared, and the batteries, armed with twenty-one guns and seven five-and-a-half-inch howitzers, opened on the 25th, but were so vigorously answered, that one howitzer was dismounted, and several artillery and engineer officers killed. Nevertheless the San Roque was silenced, the garrison of the Picurina so galled by marksmen that none dared look over the parapet, and as the external appearance of that fort did not indicate much strength General Kempt was charged to assault it in the night.