Alesandro Volta, Italian physicist and inventor, c 1800.
© Science Museum / Science & Society Picture Library
Engraving by Ambroise Tardieu, c 1820, after an original work by Nicolo Bettoni, c 1800. Count Alesandro Giuseppe Anastasio Volta (1745-1827) was the inventor of the voltaic pile, an early battery and the first source of current electricity. It consisted of two different metals, separated by chemicals in order to enable a flow of electricity. In 1775, he invented the electrophorus, a precursor of the induction machine, and in 1777 he invented an 'inflammable air' electric pistol. The SI (international standard) unit of electromotive force, the volt (V), is named after him.