On that day, professor of natural philosophy at the University of Pavia, Italy, Alessandro Volta sent a letter to President of the Royal Society of London Sir Joseph Banks. His letter titled On electricity excited by a simple contact of various conducting materials said among other things: “I am happy to inform You, Signor, and through You the Royal Society, about some remarkable results that I have arrived at… The main one lies in development of a device similar to the Leyden jar or electric machine with low charge in its action, i.e., vibration that one feel with a hand, which, however, features steady operation, i.e., delivers uninterrupted current of electric fluid.” Thus Sir Joseph was the first person to learn about the greatest invention which French scientist Arago, contemporary of Volta, compared to the telescope and steam-engine machine. This device having the form of alternating copper and zinc disks interleaved with damp woolen cloth in between them was called Voltaic pile for a long time. Today, it is called either a galvanic element or electric battery.