If the siege, in spite of the efforts of the besiegers, promised to be a long one, a blockade was the sole remaining means of reduction, though this was a thing difficult to carry out with forces which were not permanent, and which were generally far from numerous. It therefore became necessary for the besieger to protect his approaches by wooden, earthen, or even stone works, constructed under cover of the night, and solid and lofty enough to enable his archers to aim right on to the battlements of the besieged place. Wooden towers, several stories high, were also frequently resorted to, put together piece by piece at the edge of the moat, or constructed out of bow-shot, and subsequently rolled on wheels to the foot of the walls (Fig. 59). At the siege of Toulouse, in 1218, a machine of this kind was built by the order of Simon de Montfort, capable of accommodating, according to the ballad of the “Albigeois,” five hundred men. [Illustration: Fig. 60.--Siege of a Town: Summons to lay down the arms and open the gates.--From a Copper-plate in the “Kreigsbuch” of Fronsperger.] When the missiles hurled from the higher stories of these towers--termed _chattes_ in the south, _chats_, _châteaux_, _bretesches_, in the north--had driven the besieged from their ramparts and battlements, a movable bridge was lowered across the moat, and a hand-to-hand struggle then took place (Fig. 59). The besieged, to prevent or retard the approach of these dreaded towers, were accustomed to hurl immense stones and lighted darts against them, or to undermine or inundate the ground on which they stood, so that their own weight might cause them to topple over. [Illustration: Fig. 61.--Capture of a Town: The Garrison surrendering and throwing themselves on the mercy of the captors.--Miniature from the “Histoire du Monde,” Manuscript of the Fourteenth Century (Library of M. Ambroise Firmin-Didot).] Besides the means we have just described, there still remained the sap and the mine. Miners, equipped with pickaxes, were sent into the ditch under the protection of a body of archers. A sloping roof, covered with mantlets, sheltered them from the missiles of the besieged. They then pierced the wall, stone by stone, till they had made a hole large enough to allow the passage of several soldiers at once, while the sappers put the finishing stroke to the aperture. The besieged, observing in what direction the enemy was pursuing his operations, strove to concentrate all his means of defence at this point. Sometimes he attempted to crush the miners with immense stones or pieces of wood, sometimes he poured molten lead or boiling oil over them, sometimes, by hastily constructing a fresh wall in rear of the one the miners were breaking through, he gave the latter the trouble of beginning their work all over again just as they thought it was complete.