Greek and Roman artillery

The Greeks and Romans both made extensive use of artillery for shooting large arrows, bolts or spherical stones or metal balls.

Five Greek and Roman sources have survived: two treatises by Heron of Alexandria, Belopoeika and Cheiroballistra; and the books by Biton of Pergamon, Philo of Byzantium and Vitruvius[3]The earliest artillery pieces, like gastraphetes, were driven by large composite bows.

According to Marsden's analysis of ancient sources, they were invented in Syracuse in 399 BC, when tyrant Dionysius I gathered there an assembly of expert craftsmen to conduct a research on new armament.

Metal springs were not sufficiently resilient at that time,[5] and both the traction and counterweight trebuchet were unknown to the Greeks and Romans.

Originally, catapulta (καταπέλτης ὀξυβελής) meant an arrow- or bolt-throwing engine, and a ballista (καταπελτης λιτοβολος or πετροβολος) was a more powerful machine primarily designed for throwing stones.

Thus, in the 4th century CE catapulta indicates a one-armed stone-throwing engine, also known as onager, while ballista means a two-armed piece which shoots bolts only.

[6] According to Schramm, Marsden and their followers, this distinction reflects the difference in the shape of the detail of the frame which is called "hole carrier".

The main parameter that determines the sizes of all parts of the machine is the weight of the projectile or the length of the bolt (arrow).

A typical ballista could throw a stone weighing 1 talent (60 minae = 26.2 kilograms (58 lb))) at the distance of 400 yd (370 m).

Much longer ranges were claimed by Athenaeus Mechanicus "...a three-span catapult shot 700 yd (640 m) (three and half stades); its springs weighted twelve minae.

[5] Athenaeus of Naucratis mentions a catapulte designed by Archimedes, which could throw a three talent stone at the distance of one stade.

[9] Polybius (VIII,7,9) writes that catapults used to defend Syracuse during the siege by Marcellus were throwing stones of 10 talents (262 kilograms (578 lb))).

When describing the siege of Jerusalem by Titus, Josephus writes that "the stone balls that were being hurled weighted one talent and traveled two or more stades (400 yd (370 m))".

The heavy stone-throwing pieces were used to destroy the walls, while the lighter arrow-shooting pieces to clear the walls from the enemy defending them[5] Sometimes ballistae were used to fire extraordinary projectiles, like pots with snakes, or even parts of dead bodies, with the purpose of terrifying the enemy.

In many cases only few essential parts of artillery pieces were transported, the rest could be made on the place of a siege if timber was available.