With a whizzing sound, the end of the beam traced a bow of fire, and the barrel was shot forth, leaving a long and luminous trail behind it; it struck the wooden tower, and in bursting spread a sheaf of white flames which seemed to cling to the woodwork. The engine, lowered anew, sent a second barrel and a third. The wooden tower then resembled a furnace (Fig. 40). [Illustration: FIG. 40.--NIGHT SORTIE OF THE GARRISON OF THE CASTLE.] Great was the agitation among the guard of the besiegers, and the defenders could hear their shouts from the ramparts. Taking advantage of their confusion, Anseric had the barrier of the lists opened, and followed by two hundred men, went at full speed to the contravallation, passed through the central gate, which was but slightly guarded, and turned to the left, passing along the interior of the enemy's earthwork. The Burgundians had betaken themselves to the tower to try to extinguish the flames. The besieged rushed upon the disorderly mass, most of them being unarmed. The baron had also gone out with a second body to protect his nephew's retreat. The duke heard the shouting from the abbey, saw the fire, and immediately gave orders to march forward. But during the last hours of night, men are not very active. Before help arrived, Anseric had had time to kill or put to flight all who were guarding the contravallation. He could therefore re-enter the lists at his leisure, and without having lost a single man; some few being wounded. Daylight revealed to the duke the smoking remains of one of his towers. This sally raised the courage of the besieged; none of them, except those who had been in the wars of the Crusaders, knew the effects of the Greek fire. They deemed themselves, thenceforth, invincible. This was the baron's object in planning this attack, whose result was otherwise of little value to the besieged.