Tiberius Alexander, to whom the remark was addressed, shrugged his shoulders. “Mere outworks, Cæsar. What we have done is child’s play compared with what remains to be done.” Titus began to be of the same opinion as he stood amid the fast dismantling Acra, and surveyed a long chain of defiant fortresses. Before him as he looked southwards rose the rugged escarpment of Mount Zion, forty feet high, its edge surmounted by a lofty wall, whose circuit included those magnificent towers, Hippicus, Phasaelus, and Mariamne, each a citadel in itself. Above him, on his left hand, soared the temple-fortress, and adjacent to it the Turris Antonia, this last standing on a rock, which rock was not only seventy-five feet high, but had its perpendicular sides cased with smooth marble! After deliberating with his staff Titus resolved to make a simultaneous attack on Mount Zion and on Antonia. But how to reach these strongholds elevated in mid-air? There was but one way, by the raising of banks--a stupendous operation! But the Romans were familiarized with such tasks, and, animated by the same resolute spirit as their general, they set to work with a fiery energy that nothing could daunt. Owing to the scarcity of earth, timber and fascines were largely used in the erection of these works, to such an extent indeed, that not a tree remained within sight of Jerusalem. The sylvan beauty of the landscape vanished; the Jewish people, looking far and wide from the city walls, could see around them nothing but a treeless and desolate waste. On the seventeenth day a huge embankment faced the northern side of Antonia, but just when the engines planted upon it were beginning to play, the Romans, to their consternation and dismay, found the whole mound slowly beginning to sink. As the rate of subsidence varied in different parts, chasms began to yawn, the rams and towers rolled this way and that, crashing into each other with destructive effect; men found themselves entangled among the machines, overwhelmed with earth, suffocated with dust; a prodigious quantity of smoke burst forth from the embankment, followed by darting tongues of flame. It was death to remain longer upon it, and the amazed and affrighted Romans, running in all directions, leaped from the mound. The cause of it all soon became clear. John of Giscala and his Zealot crew, toiling underground with an energy almost superhuman, had driven a vast mine beneath the Roman agger, a mine whose roof and supports were formed of timber, daubed with bitumen, sulphur, and other combustibles. The ignition of these supports caused the engulfing of the bank, and the complete destruction of the engines. “Seest thou what John hath wrought?” cried Simon to his followers. “Shall we be outdone by him?”