Catapults

Balistas

Deffinition: an ancient military engine for throwing stones or other missiles. (Webster Dictionary)

The word Ballista comes from the Greek work 'Ballistes' which means to throw. In England the ballista was also known as the Ingenium which is Latin for ingenious device. Which it is. The ballista was designed after a cross bow. It was designed to shoot giant darts or arrows a great distance. These devices were not made and carried along during a seige. They were technically a "made to order" weapon. They were way to heavy and cumbersome to bring along. The commander would look at the situation and then command his men to make some while waiting. They would then use the weapons during the seige.

How it works:

This weapon uses tension to work. There are two skeins of string on either arm of the device. The string is loosened and pulled back. An arrow is placed in the waiting position. The arms are then pulled back and tightened. This creates the tension that is needed to get the arrow to propel forward. This tension also creates potential energy. Potential energy is what causes an object to move. It is when an object is either at the top of a hill or has a buiild up of potential. This is a build up of potential. So when the string is released it causes all the build up of potential to be changed to kinetic energy which makes the arrow move. The greater the build up, the further the arrow will go.