Fig. 30. (top) Fig. 31. (middle) Fig. 32. (bottom)
“Now in the spiral M is stuck a knitting-needle, which, as the figure shows, is fastened into a sounding-board. A lid provided with second sounding-board may be clapped over the spiral, and the tone be thereby greatly strengthened.
“If now, tones are produced before the mouth-piece S, whilst one sings into the same or whilst one blows organ-pipes, one at once hears at the reproducing apparatus a peculiar creaking noise which is independent of the pitch of the tones produced at the interrupting apparatus, but, beside this, those tones are themselves reproduced by the steel wire distinctly perceptibly, and indeed Reis found that this is the case for all tones between F and f''.
“In Reis’s experiments the interrupting apparatus was 300 feet distant from the spiral, and was indeed set up in another house with closed doors. But since the length of the conducting wire can be extended just as far as in direct telegraphy, Reis gave to his apparatus the name Telephone (Jahresbericht des physikalischen Vereins zu Frankfurt-a.-M. für 1860/61).”
[15.] Extract from Pisko’s ‘Die Neueren Apparate der Akustik.’
[This book, ‘The more recent Apparatus of Acoustics,’ by Dr. Francis Joseph Pisko, Professor of Physics in the Gewerbeschule in Vienna, was published at Vienna in 1865. At that time the novelties in acoustics were König’s apparatus for the graphic study of sounds, König’s manometric flames, Schaffgotsch’s singing flames, Helmholtz’s ‘Researches on the Quality of Sounds,’ Duhamel’s Vibrograph, Scott and König’s Phonautograph, and Reis’s Telephone. The account given of the latter is more detailed in some respects than any other published at the time.]
Page 94.—Principle of the “Telephon” of Reis.