helepolis

• a besieging engine, invented by Demetrius Poliorcetes, Vitr. 10, 22; Amm.23, 4.

HELE´POLIS(ἑλέπολις). When Demetrius Poliorcetes besieged Salamis in Cyprus B.C. 306, he caused a machine to be constructed, which he called the taker of cities. Its form was that of a double cube, 45 cubits square and 90 high. It rested on four wheels, each 8 cubits high. It was divided into nine stories, the lower of which contained machines for throwing great stones, the middle large catapults for throwing spears, and the highest, other machines for throwing smaller stones, together with smaller catapults. It was manned with 200 soldiers, basides those who moved it by pushing the parallel beams at the bottom. (Diod. 20.48.)

At the siege of Rhodes, in the following year, Demetrius employed a helepolis of still greater dimensions and more complicated construction/ Besides wheels it had castors (ἀντίστρεπτα), so as to admit of being moved laterally as well as directly. Its form was pyramidal. The three sides which were exposed to attack were rendered fire-proof by being covered with iron plates. In front each story had port-holes, which were adapted to the several kinds of missiles, and were furnished with shutters that could be opened or closed at pleasure, and were made of skins stuffed with wool. Each story had two broad flights of steps, the one for ascending, the other for descending. (Diod. 20.91; Plut. Demetr. 21; compare Vitr. 10.22.) This helepolis was constructed by Epimachus the Athenian; and a much esteemed description of it was written by Dioclides of Abdera. (Athen. 5. p. 206 d.) It was no doubt the greatest and most remarkable engine of the kind that was ever erected. In subsequent ages we find the name of helepolis applied to moving towers which carried battering-rams, as well as machines for throwing spears and stones. Engines of this kind were used to batter the walls of Jerusalem at the siege under Titus (Joseph. B. J. 2.19.9; 3.6.2). One described by Ammianus does not differ much from the earlier model (Ammian. 23.4.10); we find them likewise in the Byzantine period (Agathias, 1.18; Nicet. Chon. Jo. Comnen. p. 14 b). [ARIES; TORMENTUM. ]

(ἑλέπολις). Literally, “destroyer of cities;” the name given to an engine invented by Demetrius Poliorcetes (q. v.) for besieging fortified places, consisting of a square tower placed upon wheels, and run up to the height of nine stories, each of which was furnished with machines for battering and discharging projectiles of enormous size and weight (Diod. Sic. xx. 48, 91; Vitruv. x. 22; Ammian. xxiii. 4, 10). See Demetrius, p. 485.