The troops were under arms, and disposed in the most convenient manner, as near the head of the bridge as the necessity of keeping them hidden would permit; and at eight o’clock, all being prepared, and the moon shining bright, twenty men were sent a little below the bridge, and directed to open an oblique fire of musketry against the entrenchments. This being replied to, and the attention of the Portuguese attracted, a sapper, dressed in dark grey, crawled out, and pushed with his head a barrel of powder, which was likewise enveloped in grey cloth to deaden the sound, along that side of the bridge which was darkened by the shadow of the parapet: when he had placed his barrel against the entrenchment covering the Portuguese mine, he retired in the same manner. Two others followed in succession, and retired without being discovered; but the fourth, after placing the barrel, rose on his feet and ran back, but was immediately shot at and wounded. The fire of the Portuguese was now directed on the bridge itself; but as the barrels were not discovered, after a time it ceased; and a fifth sapper advancing like the others, attached a sausage seventy yards long to the barrels. At two o’clock in the morning the whole was completed; and as the French kept very quiet, the Portuguese remained tranquil and unsuspicious. Brochard had calculated that the effect of four barrels exploding together would destroy the Portuguese entrenchments, and burn the cord attached to their mine. The event proved that he was right; for a thick fog arising about three o’clock, the sausage was fired, and the explosion made a large breach. Brochard, with his sappers, instantly jumped on to the bridge, threw water into the mine, cut away all obstacles, and, followed by a column of grenadiers, was at the other side before the smoke cleared away. The grenadiers being supported by other troops, not only the suburb, but the camp on the height behind were carried without a check, and the Portuguese dispersing, fled over the mountains. The execution of captain Brochard’s bold, ingenious, and successful project, cost only seven or eight men killed; while in the former futile attempts above a hundred and eighty men, besides many engineer and artillery officers, had fallen. It is, however, a singular fact that there was a practicable ford near the bridge, unguarded, and apparently unknown to both sides. A short time after the passage of the Tamega, general Heudelet, marching from Braga by Guimaraens, entered Amarante. Laborde occupied the position abandoned by Sylveira, and detachments were sent up the left bank of the river to Mondin: but Loison pursued the fugitives to the heights of Villa Real and Mezamfrio. The Portuguese guarding the passage at Canavezas, hearing of the action, destroyed their ammunition, and retired across the Douro without being overtaken.