Gabriel Lippmann (1845-1921) delivering a lecture on sound propagation in solid bodies. He is demonstrating that sound can be carried along a metal bar, using a violin to amplify the vibrations. Gabriel Lippman was a French classical physicist who gained fame for his work in optics and electricity. In 1908 he received the Nobel Prize in Physics for producing the first colour photograph. The technique used was too complicated though to succeed commercially. Taken from Physique Populaire, 1891.