The next memorable instance is the siege of Rhodes by Demetrius Polyorcetes, who brought forward a newly invented machine, called Helepolis, (taker of Cities), with a variety of other engines, and employed 30,000 men in the management of them.
Balistæ at Cremona.
Tacitus mentions an extraordinary engine, used by the 15th Legion at the battle of Cremona, against the troops of Vespasian. It was a Balista of enormous size, which discharged stones of weight sufficient to crush whole ranks at once. Inevitable ruin would have been the consequence, had not two soldiers, undiscovered, cut the ropes and springs. At length, after a vigorous assault from Antonius, the Vittelians, unable to resist the shock, rolled down the engine, and crushed numbers of their assailants, but the machine, in falling, drew after it a neighbouring tower, the parapet, and part of the wall, which afforded the besiegers easier access to the city.
Balistæ at siege of Jotapata.
Josephus relates that at the siege of Jotapata, “a stone from one of the Roman engines carried the head of a soldier, who was standing by him, three furlongs off;” that “lances were thrown with great noise, and stones, weighing 114lbs. troy, “together with fire and a multitude of arrows.” Dead men and horses projected.The dead bodies of men and horses were also thrown at this siege, and at that of Jerusalem, A. D. 70, to inspire terror.
Form of Balistæ.
The earliest form of Balistæ appears to have been a very long beam, suspended in a frame on a centre of motion, one end being considerably longer than the other. To the short end was attached a great weight, such as a chest filled with earth or stones. To the longer end a sling was affixed, in which, after being drawn down, a stone was placed, and on being suddenly let go, the long end flew up, and discharged the stone with great violence.
Form of Catapultæ.
Catapultæ were sometimes constructed to discharge a flight of arrows at once, by placing them on a rack, and causing a strong plank, previously drawn back, to strike against their ends. The more perfect engines of the Romans were all dependent on the elasticity of twisted cords made of flax, hemp, the sinews or tendons of animals, from the neck of the bull, or legs of the deer species, and ropes formed of human hair were preferred to all others, as possessing greater strength and elasticity. Catapultæ were immensely powerful bows, drawn back by capstans, levers, or pulleys, having only a single cord for the arrow, ([plate x.]), but the Balistæ had a broad band, formed of several ropes to project the stone, which was placed in a kind of cradle, like a cross-bow. ([plate xii.])
Balistæ at battle of Hastings 1066