"I doubt it," replied the Roman, "but every missile that comes through the window must take its toll, as we are so crowded here that all of us cannot get out of range." The legionaries that had been summoned to the throne-room had been held at the small doorway by a handful of gladiators and the defenders had been able to close and bar the stout oaken door. For a time there had been silence in the throne-room and no attempt was made to gain entrance to the room upon that side; while upon the garden side two or three attempts to rush the window had been thwarted, and now the legionaries held off while the small ballista was being dragged into place and trained upon the palace wall. Dilecta having been placed in an angle of the room where she would be safest, Tarzan and his lieutenants watched the operations of the legionaries in the garden. "They do not seem to be aiming directly at the window," remarked Cassius Hasta. "No," said Praeclarus. "I rather think they intend making a breach in the wall through which a sufficient number of them can enter to overpower us." "If we could rush the ballista and take it," mused Tarzan, "we could make it rather hot for them. Let us hold ourselves in readiness for that, if their missiles make it too hot for us in here. We shall have some advantage if we anticipate their assault by a sortie of our own." A dull thud upon the door at the opposite end of the room brought the startled attention of the defenders to that quarter. The oak door sagged and the stone walls trembled to the impact. Cassius Hasta smiled wryly. "They have brought a ram," he said. And now a heavy projectile shook the outer wall and a piece of plaster crumbled to the floor upon the inside--the ballista had come into action. Once again the heavy battering-ram shivered the groaning timbers of the door and the inmates of the room could hear the legionaries chanting the hymn of the ram to the cadence of which they swung it back and heaved it forward. The troops in the garden went about their duty with quiet, military efficiency. Each time a stone from the ballista struck the wall there was a shout, but there was nothing spontaneous in the demonstration, which seemed as perfunctory as the mechanical operation of the ancient war-engine that delivered its missiles with almost clocklike regularity. The greatest damage that the ballista appeared to be doing was to the plaster on the inside of the wall, but the battering-ram was slowly but surely shattering the door at the opposite side of the room. "Look," said Metellus, "they are altering the line of the ballista. They have discovered that they can effect nothing against the wall." "They are aiming at the window," said Praeclarus. "Those of you who are in line with the window lie down upon the floor," commanded Tarzan. "Quickly! the hammer is falling upon the trigger."