SCIENCE IN THE INDUSTRIAL WORLD 







to a diaphragm. This instrument worked perfectly in 

 simply recording sounds; but it did not reproduce these 

 sounds, and apparently the inventor made no attempts 

 to do so. His claim to priority in inventing a speak- 

 ing phonograph, therefore, is absolutely groundless. 

 A more reasonable claim might have been made by the 

 Frenchman, M. Charles Cros, who, in April, 1877, sent 

 to the Academy of Science, in Paris, a paper describing 

 the way in which an instrument might be made that 

 would reproduce such sounds as the human voice. But 

 this was simply a description of a possible instrument, 

 the actual construction of which had not been attempted. 

 And when Abbe Leblanc, a short time later, constructed 

 an instrument after the method described by Cros, it 

 failed utterly as a sound-producer. It is evident, 

 therefore, that Edison's claim to the invention of the 

 first phonograph stands absolutely unchallenged. 



In contrast to the wonderful effects that may be 

 produced by this instrument is the simplicity of the con- 

 struction of the instrument itself. The Edison phono- 

 graph of 1877 was fitted with a cylinder covered with tin- 

 foil for receiving the impression of the sound waves. 

 This cylinder was so arranged that, as it revolved, it 

 moved at a definite rale of speed from right to left, this 

 movement being controlled by the action of screw 

 threads. Above this cylinder, and arranged so that a 

 needle point pressed into the tin-foil, was the recorder. 

 This consisted of a cylinder about two inches in diam- 

 eter, over the lower end of which was stretched a dia- 

 phragm of parchment or gold-beater's skin, with a needle 

 or recording point fastened to the centre. When sounds 



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