Volta pistol, posibly late 18th Century.
© Science Museum / Science & Society Picture Library
This instrument was invented by Count Alesandro Anastasio Volta (1745-1827), the Italian physicist and inventor of the voltaic pile, an early battery. A Volta pistol is a pistol-shaped device that is filled with an explosive mixture of gases (hydrogen and air or oxygen for example) and closed with a cork. An electrical discharge is then pased acros a small spark gap inside the pistol, using electrodes pasing through the barrel. The spark ignites the mixture and shoots a cork out of the end of the pistol.