ON EDISON" S TALKING-MACHINE. 719 



1 



ON EDISON'S TALKING-MACHINE. 1 



By ALFRED M. MAYER. 



MR. THOMAS A. EDISON has recently invented an instrument 

 which is undoubtedly the acoustic marvel of the century. It is 

 called the " Speaking Phonograph," or, adopting the Indian idiom, 

 one may aptly call it " The Sound- Writer who talks.'''' Much curiosity 

 has been expressed as to the workings of this instrument, so I purpose 

 giving an account of it. 



All talking-machines may be reduced to two types. That of Prof. 

 Faber, of Vienna, is the most perfect example of one type ; that of 

 Mr. Edison is the only example of the other. 



Faber worked at the source of articulate sounds, and built up an 

 artificial organ of speech, whose parts, as nearly as possible, perform 

 the same functions as corresponding organs in our vocal apparatus. 

 A vibrating ivory reed, of variable pitch, forms its vocal chords. 

 There is an oral cavity, whose size and shape can be rapidly changed 

 by depressing the keys on a key-board. A rubber tongue and lips 

 make the consonants ; a little windmill, turning in its throat, rolls 

 the letter 7, and a tube is attached to its nose when it speaks French. 

 This is the anatomy of this really wonderful piece of mechanism. 



Faber attacked the problem on its physiological side. Quite dif- 

 ferently works Mr. Edison : he attacks the problem, not at the source 

 of origin of the vibrations which make articulate speech, but, con- 

 sidering these vibrations as already made, it matters not how, he 

 makes these vibrations impress themselves on a sheet of metallic foil, 

 and then reproduces from these impressions the sonorous vibrations 

 which made them. 



Faber solved the problem by reproducing the mechanical causes 

 of the vibrations making voice and speech ; Edison solved it by ob- 

 taining the mechanical effects of these vibrations. Faber reproduced 

 the movements of our vocal organs ; Edison reproduced the motions 

 which the drum-skin of the ear has when this organ is acted on by 

 the vibrations caused by the movements of the vocal organs. 



Figs. 1 and 2 will render intelligible the construction of Mr. Edi- 

 son's machine. A cylinder, F, turns on an axle which passes through 

 the two standards, A and B. On one end of this axle is the crank, 

 D ; on the other the fly-wheel, E. The portion of this axle to the 

 right of the cylinder has a screw-thread cut on it, which, working in 

 a nut, A, causes the cylinder to move laterally when the crank is 



1 The figures in this article are taken from " Sound, a Series of Simple, Entertaining, 

 and Inexpensive Experiments in the Phenomena of Sound, for the Use of Students of 

 every Age." By Alfred M. Mayer. Vol. ii. of "Experimental Science Series for Begin- 

 ners." (Now in press and soon to be published by D. Appleton & Co.) 



