“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. 51. (_a._) Allied to the Membrane Phonautograph is the “Telephon” of Reis[34] (Fig. 33). Upon the little membrane, _m m_, in the middle, is fastened with adhesive wax the round end _s_ of a light strip of platinum, _n s_, so that the platinum strip can join in with all the vibrations of the membrane. Very near to the central end, _s_, of the little platinum strip, _n s_, a platinum spike stands, in such a way that it is brought into contact, by the vibrations of the membrane, with the platinum strip that vibrates with the latter. Suppose now that the outer end, _n_, of the platinum strip and the platinum spike are connected with the poles of a galvanic battery, then, by the vibration of the membrane the galvanic current will, according to the phase of the vibration, be alternately established and interrupted. Inserted in this circuit, an electro-magnetic bell, or an electro-magnetic telegraph, will give signals to great distances that somebody is speaking;[35] though, obviously, it cannot inform _what_ is being spoken. [Illustration: Fig. 33.]