This model demonstrates the "steam cannon" or Architronito. Leonardo da Vinci described it as "a machine of fine copper, an invention of Archimedes, and it throws iron balls with great noise and violence." Petrarch also attributed Archimedes with the invention of firearms.. The steam cannon works by means of a brazier that heats the chamber. Water is inserted through a valve and immediately turns to steam, providing the thrust required to hurl the projectile.