Heroes of the Telegraph

It is reported that on another trial the light from the star Arcturus, when focussed on the vulcanite, was capable of deflecting the needle of the galvanometer. When gelatine is substituted for vulcanite, the humidity of the atmosphere can also be measured in the same way. Edison's crowning discovery at Menlo Park was the celebrated 'phonograph,' or talking machine. It was first announced by one of his assistants in the pages of the SCIENTIFIC AMERICAN for 1878. The startling news created a general feeling of astonishment, mingled with incredulity or faith. People had indeed heard of the talking heads of antiquity, and seen the articulating machines of De Kempelen and Faber, with their artificial vocal organs and complicated levers, manipulated by an operator. But the phonograph was automatic, and returned the words which had been spoken into it by a purely mechanical mimicry. It captured and imprisoned the sounds as the photograph retained the images of light. The colours of Nature were lost in the photograph, but the phonograph was said to preserve the qualities even of the human voice. Yet this wonderful appliance had neither tongue nor teeth, larynx nor pharynx. It appeared as simple as a coffee-mill. A vibrating diaphragm to collect the sounds, and a stylus to impress them on a sheet of tinfoil, were its essential parts. Looking on the record of the sound, one could see only the scoring of the stylus on the yielding surface of the metal, like the track of an Alpine traveller across the virgin snow. These puzzling scratches were the foot-prints of the voice.