wicker hurdles on the sides. The entire shelter would then be covered with a fireproof material such as uncured hides. According to Apollodorus of Damascus, the shelter should be fixed to the ground while the ram was being used to both prevent skidding and strain on the axles from the weight of the moving apparatus. This would also increase the strength of the impact on the walls. Siege tower According to Josephus, the Roman siege towers at Jotapata were 50 feet high and iron-plated to protect them from fire; those at Masada were reported to be 75 feet high. It was possible to have many different devices on siege towers, such as artillery, draw bridges and rams. Those at the top of the tower were to keep defenders off the walls while those below them attempted to breach the wall using ramps. In the battle of Jerusalem in 70 AD the Romans began assault on the third defensive wall within Jerusalem, the tower stood 75 ft tall and was compromised when the Jewish resistance tunneled underneath the tower leading it to collapse. Following a basic design, details of tower construction varied from siege to siege and there is no known treatise which specifies at which level siege equipment should be placed. Vegetius noted that, “besiegers sometimes built a tower with another turret inside it that could suddenly be raised by ropes and pulleys to over-top the wall”. Mine Mines could be dug under city walls as a means of entering a city secretly and capturing it but were more frequently constructed to weaken city walls. Once dug, sappers would underpin the walls with wood and cause the walls to collapse by firing the supports with resin, sulfur and other incendiary materials. Corvus In chapter 1.22 "The Victory of Mylae" of his History, Polybius writes:Now their ships were badly fitted out and not easy to manage, and so some one suggested to them as likely to serve their turn in a fight the construction of what were afterwards called "crows". Corvus means "crow" or "raven" in Latin and was the name given to a Roman boarding device first documented during the First Punic War against Carthage. Polybius goes on to describe this siege engine as a bridge used to span the distance between two ships in battle. The device was a plank, 4 ft wide and 36 ft long, affixed to