  thumb|250px|right|counterweight trebuchet constructed on the design of the "warwolf"  a trebuchet (french trÃ©buchet) is a type of catapult that was used as a siege engine in the middle ages. it is sometimes called a counterweight trebuchet or counterpoise trebuchet, to distinguish it from an earlier weapon called the traction trebuchet, which employed pulling men working the mechanism. the counterweight trebuchet appeared in both christian and muslim lands around the mediterranean in the 12th century. it could fling projectiles weighing up to 350 pounds (160&nbsp;kg) at or into enemy fortifications. its use continued into the 15th century, well after the introduction of gunpowder. the trebuchet's technical constructions were lost at the beginning of the 16th century. in 1984, the french engineer renaud beffeyte made the first modern reconstruction of a trebuchet, based on documents from 1324.http://armedieval.fr == basic design == a trebuchet works by using the energy of a raised counterweight to throw a projectile. a long beam is attached to an axle. at the short end of the beam is attached the counter weight. the long end of the beam is pulled down, raising the counterweight. a sling, which has a pouch containing the projectile, is attached to the long end of the beam. upon releasing the trigger, the sling and the beam swing upward, pivoting on the axle toward the vertical position, whereupon one end of the sling releases, opening the pouch and allowing the projectile to fly towards the target. the stored energy of the counterweight is transferred efficiently to the projectile.siano, pp 5,6 and 37 modern-day enthusiasts have varied the first design, especially to control the path of the counterweight for increased efficiency. the three chief distinguishing characteristics of a trebuchet are: * the machine is powered exclusively by gravity; most often directly by means of a 
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