Prepare for attack! Man the siege engines. This project is all about building a scaled version of a medieval trebuchet.
A trebuchet ( /ˈtrɛbəʃɛt/ treb-ə-shet or /ˌtrɛbjʊˈʃɛt/ treb-ew-shet;[1] French: trébuchet) is a siege engine that was employed in the Middle Ages. It is sometimes called a “counterweight trebuchet” or “counterpoise trebuchet” in order to distinguish it from an earlier weapon that has come to be called the “traction trebuchet”, the original version with pulling men instead of a counterweigh. (http://en.wikipedia.org/wiki/Trebuchet)