Helpful Catapult Links:

• http://www.catapults.info/

• https://www.northallegheny.org/cms/lib9/PA01001119/Centricity/Domain/1134/Catapults.pdf

• http://www.virtualtrebuchet.com

• http://www.stormthecastle.com/catapult/index.htm

• http://www.globalspec.com/Trebuchet/

• http://www.instructables.com/id/How-To-Build-A-Catapult/

• http://monsterguide.net/how-to-build-a-catapult

• http://hubpages.com/hub/How-to-Build-a-Catapult---An-Illustrated-Guide

• http://www.building-a-catapult.com/index.html

• http://www.howtobuildcatapults.com/

• https://historyplex.com/catapult-history
• https://www.youtube.com/watch?v=hKtb8pSpUHY