Tin-foil phonograph, known as the demonstration phonograph

The French public first saw Edison's phonograph at the 1878 Universal Exhibition. The operator wrapped tin foil around a cylinder, cranking it while shouting into a mouthpiece containing the same kind of membrane used in Alexander Graham Bell's telephone. The sound's vibrations moved a steel needle that etched grooves into the foil. The now-recorded voice was amplified and played back by means of a megaphone placed on the mouthpiece. "It is impossible to realize what an amazing impression the little voice crackling out of the instrument made without hearing it; you are doubtful until the last second, and when the distinct, though weak, sounds reach the ear, you feel astonished and satisfied […]," wrote a journalist in La Nature in 1878.