The onager was an imperial-era Roman torsion powered siege engine; in other words, a small catapult. that threw stones into the air, as did the hooves of the wild ass, the onager, which was native to the eastern part of the empire.
A torsion siege engine is a type of artillery that utilizes torsion to launch projectiles. They were It lists the building's inventory that included torsion catapults and its components such The Romans obtained their knowledge of artillery from the Greeks. .. euthytonos ("straight-spring"), onager ("wild ass"), ziyar, qaws al-ziyar.
In later times it was variously known as a mangonel, a nag, and a gonne. the Romans called their catapults onagers, or wild asses, for the way in which their.