Barton, Edwin H. (Edwin Henry), b. 1858 · London, Macmillan and Co., limited · leaf 353
<ti … ~j H —Dr. Erskine-Murrays Phonoscope. scope, it is of the utmost importance that the mirror Eshould be very light and quite free to move, but withoutshake, and that the membrane should be somewhat slack.The diameter of the membrane must also be chosen withreference to the pitch of the sounds for…
Sound
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