The great mass of the Monte Junto appears to lead perpendicularly on to the centre of the first ridge; but stopping short at a few miles distance, sends a rugged shoot called the Sierra de Barragueda in a slanting direction towards Torres Vedras, from which it is only divided by a deep defile. From this conformation it results, that an army marching from the Mondego to Lisbon, must either pass behind the Monte Junto, and follow the line of the Tagus, or keeping the western side of that mountain, come upon the position of Torres Vedras. If sir Arthur Wellesley had adopted the first line of operations, his subsistence must have been drawn by convoys from the Mondego, the enemy’s numerous cavalry would have cut his communications, and in that state he would have had to retreat, or to force the positions of Alhandra, Alverca, and finally the heights of Bellas, a strong position the right flank of which was covered by the creek of Saccavem, and the left flank by the impassable Sierra dos Infiernos. On the other line Torres Vedras was to be carried, and then Mafra or Montechique, following the direction of Junot’s retreat. If Mafra was forced (and neither it nor Montechique could be turned), a line of march, by Cassim and Quelus, upon Lisbon would have been opened to the victors; but that route, besides being longer than the road through Montechique and Loures, would, while it led the English army equally away from the fleet, have entangled it among the fortresses of Ereceira, Sant Antonio, Cascaes, St. Julians, and Belem. Again, supposing the position of Montechique to be stormed, the heights of Bellas offered a third line of defence, and lastly, the citadel and forts of Lisbon itself would have sufficed to cover the passage of the river, and a retreat upon Elvas would have been secure.