36. The Lethal Trebuchets
Traditional catapults relied on torsion or tension to store energy prior to release. By contrast, trebuchets relied on gravity: a heavy weight on one side of a pivot, with a long arm from which a stone was flung on the other side. Trebuchets were faster and easier to construct, and used relatively few expensive materials, such as the pricey elastic ropes needed for torsion catapults.
On the downside, trebuchet ranges were shorter than those of torsion catapults. However, trebuchets made up for that with consistency. Torsion catapults were not consistent, with factors such as rope dampness or loss of elasticity causing the impact ranges to vary. Trebuchets by contrast relied on the constants of gravity and a fixed weight for energy. Once ranged in, they would hit the same spot if given the same weight projectile.