"DaVinci Crossbow" by Leonardo da Vinci - http://www.sandia.gov/tp/SAFE_RAM/CRSBW.HTM. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:DaVinci_Crossbow.JPG#/media/File:DaVinci_Crossbow.JPG
DaVinci_Crossbow
"DaVinci Crossbow" by Leonardo da Vinci - http://www.sandia.gov/tp/SAFE_RAM/CRSBW.HTM. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:DaVinci_Crossbow.JPG#/media/File:DaVinci_Crossbow.JPG