The Scorpio - a Roman torsion siege engine and field artillery piece, often referred to as the "Scorpion" due to its stinging nature.   The Scorpio was described in detail by the early-imperial Roman architect and engineer Vitruvius in the 1st century BC. It had two main versions: a horizontal two-armed variety similar to a ballista, and a one-armed, vertical version known as an onager. The Scorpio was made of a sturdy wooden frame with sinew-springs (tormenta) for power. An arm with iron hooks launched projectiles like stones or bolts.
Usage in Battles
The Scorpio was used in several significant battles and sieges. One of the most notable mentions is during the siege of Avaricum in 52 BC, where Julius Caesar used the Scorpio as an anti-personnel weapon against the Gallic town's defenders. It was also used during the Persian Wars of Constantius II in the 4th century AD. The Scorpio was typically mounted on carts (carroballistae) for increased mobility and was a crucial part of Roman artillery batteries.
 
Innovative Features
The Scorpio distinguished itself through several innovative features:
Precision and Range: It was capable of precision shooting at ranges up to 100 meters and parabolic shooting up to 400 meters. This made it effective in both close and long-range combat.
Versatility: The Scorpio could fire various projectiles, including bolts, stones, flaming missiles, and even grappling hooks.
Ease of Operation: Unlike other siege engines, the Scorpio only required one man to operate it, making it more efficient in the field.
Mobility: Being mounted on carts allowed for quick deployment and repositioning during battles.
 
Legacy
The Scorpio's design and tactical use revolutionized Roman siege warfare and battlefield tactics. Its legacy lies in demonstrating Roman ingenuity in crafting powerful and versatile siege weaponry1.