I have already made some allusion to the lines of Torres Vedras, thrown up for the defence of Lisbon by Lord Wellington. These lines consisted of three distinct ranges of defence. The first, extending from Alhandra on the Tagus to the mouth of the Zizandre on the sea-coast, was, following the inflections of the hills, twenty-nine miles long. The second, traced at a distance varying from six to ten miles in rear of the first, stretched from Quintella, on the Tagus, to the mouth of the St. Lorenzo, being 119twenty-four miles in length. The third, intended to cover a forced embarkation, should it become necessary, extended from Passo d’Arcos, on the Tagus, to the tower of Junquera, on the coast. Here an outer line, constructed on an opening of three thousand yards, enclosed an entrenched camp, designed to cover the embarkation with fewer troops, should the operation be delayed by bad weather; and within this second camp, Fort St. Julian’s, whose high ramparts and deep ditches defied an escalade, was armed and strengthened to enable a rearguard to protect both itself and the army. Of these stupendous lines, the second, whether regarded for its strength or importance, was the principal, and the others only appendages; the one as a final place of refuge, the other as an advanced work to stem the violence of the enemy, and to enable the army to take up its ground on the second line without hurry or pressure. The aim and scope of all the works were to bar those passes, and to strengthen the favourable fighting positions between them, without impeding the movements of the army. The fortifications extended to the space of fifty miles; there were one hundred and fifty forts, and not fewer than six hundred pieces of artillery mounted within them, while the river was protected by gunboats manned with British marines.