In da Vinci’s time an engineer was literally ‘a constructor of military engines’. His long-range steam cannon replaced gunpowder with water. The breech was to be kept red-hot using live coals and loaded with a cannon ball. When a small amount of water was injected into the chamber it would instantly expand into steam and project the ball out the copper barrel.
Gunpowder was the mainstay of artillery until the 1840s when nitrocellulose and nitroglycerine were discovered and combined to create powerful, stable and propellant variations, which are used today.
In the 1990s, Mike O’Dwyer from Brisbane, Australia, patented an electronic ignition system for artillery and guns capable of firing at a rate of 1.62 million rounds per minute from a multi-barrel device, creating a ‘metal storm’ of projectiles.