On 20 March 1800 Volta wrote to the Royal Society in London announcing his discovery of an electric battery, known as Volta's pile. Volta had been elected to the Royal Society of Great Britain in 1791 and chose to announce his ground-breaking discovery through the Royal Society. This engraving shows Joseph Banks reading Volta's letter to members of the Royal Society in April 1800. A Voltaic Pile is shown on the table in front of him. For the first time it became possible to produce a sustained electrical current. The importance of this discovery was immediately apparent and led to the development of electrochemistry and electromagnetism.