These first measures adopted, the duke had a ditch dug, with a mound crossing the pleasance of the castle within bowshot, and connecting the two ridges. This intrenchment of contravallation was strengthened by two wooden towers, one at each end, with an outlet near each of them, and one in the middle (Fig. 39). The castle was thus completely invested (May 15th). [Illustration: FIG. 39.] While these works were being executed, there were trifling skirmishes every day between the defenders and the besiegers. They were trying each other's strength, but nothing serious was attempted. The duke bent his whole strength towards preventing the lord of Roche-Pont and his men from escaping: he was taking his time. Baron Guy was often closeted with a certain individual whom he called his chaplain, and who had accompanied him from Palestine. In the castle, this so-called chaplain never went by any other name than the _Saracen_. He was a tall, thin personage, with dark brown skin, black eyes and hair, always dressed in a coarse grey surtout. He spoke little, and drank nothing but water; but never failed to be present at mass in the chapel of the castle, and would remain long hours in prayer. The baron asserted that he was a monk of the order of Bethlehem. Whatever he was, he had charge of the sick, and possessed remedies for wounds of all kinds. He was gentle in manner, never looked a woman in the face, was a scholar, and would read aloud so as to charm the most delicate ears. His official name was Brother Jerome. Now, during the leisure which the enemy left the besieged (who were not sufficiently numerous to offer any hindrance to the siege works of the Burgundians, and could do nothing but keep a careful look-out), it was remarked at the castle that the baron and Brother Jerome passed whole hours together, in the lower apartment of one of the towers, of which they alone had the key. Their clothes were often observed to be blackened when they came out. It was the eighth day of the investment, which appeared now to be complete (May 22nd). The baron had a secret conference with his nephew and Brother Jerome in the evening, and about six o'clock, orders were given to prepare one of the largest trebuchets, whose framing had been transported thither during the preceding night, at the western end of the lists, outside the ditch. About two o'clock in the morning, the engine was mounted, the night being still completely dark, as it would be at that season. They then tried its range against the right-hand tower of the besiegers' contravallation, with stones; and when the proper range had been secured--a point ascertained by the noise of the projectiles that fell on the woodwork--Brother Jerome placed in the lowered pouch of the stone-propeller a barrel provided with a match, and giving orders to let go the beam of the engine, set fire to the match with a brand taken from a brasier kindled for the purpose.