A Skeptical Letter to the Editor, Chicago Tribune, May 12, 1878.

THE PHONOGRAPH
To the Editor of The Tribune.

GENEVA LAKE, Wis., May 9.--It is stated that the phonograph works entirely by mechanical force, that the vibrations of the disk are conveyed by the point to tin-foil, where indentations are made corresponding to the vibrations of the disk.  It is claimed that the pressing of this point over the indentations causes the disk to vibrate in the same way as when spoken to, and with nearly the same tone and form; and it is also claimed that different sounds can be made on the disk at the same time, and these different sounds be carried back, at the same time, to the disk, and be distinctly heard.

Let us examine this statement.  Consider the force of the voice, which must be used with more than ordinary strength, which causes the point to make indentations in the tin foil.  From the nature of the tin foil, it would be impossible to make deep indentations; consequently, the force which would come to the disk from the point would be very feeble.  The point must be near enough to the tin foil to touch the lowest part of the indentation.  Has the tin foil between the indentations resisting power enough to push back the point so so [sic] as to cause vibrations which could be heard; and how could different sounds come from one indentation?

Speaking through the telephone is entirely different.  There we have the intervention of a force which flashes the sound, or what produces it, along the telegraph-wire, and causes vibrations of the corresponding disk equal, or nearly equal, to those of the disk to which the person speaks.

Has not Mr. Edison, by means of ventriloquism, been testing the credulity, or rather faith, of those who have seen such wonders in Science that they are ready to believe the impossible if learned investigators and scientists should declare its truth?

C. 

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