LSE4099135 General layout of the experiments of Heinrich Hertz (1857-1894) on electric waves - in ??s??? Physique populaire??? by Emile Desbeaux, Flammarion, 1891 by Unknown Artist, (19th century); Private Collection; (add.info.: General layout of the experiments of Heinrich Hertz (1857-1894) on electric waves - in ??s??? Physique populaire??? by Emile Desbeaux, Flammarion, 1891); Photo ?? Leonard de Selva; out of copyright.