June 7, 1883] 



NATURE 



131 



parison of the action of the transmitting part of the 

 instrument with that of the human ear upon which it was 

 founded. The author says : " How could a single instru- 

 ment reproduce at once the total action of all the organs 

 operated in human speech ? This was ever the cardinal 

 question. At last 1 came by accident to put this question 

 another way. How does our car perceive the total (or 



Fig. 1. 



Fig. 2. 



Fig. 3. 



Fig. 4. 



resultant) vibrations of all the simultaneously operant 

 organs of speech ?" He then goes on to describe the 

 action of the auditory ossicles when made the recipients 

 of sound-waves, and points out how they execute move- 

 ments and exert forces upon one another in proportion to 

 the condensations occurring in the sound-conducting 

 medium and to the amplitudes of vibration of the tym- 



panum. Having stated this law of proportion between 

 the cause and its effect, he goes on to speak of the graphic 

 method of representing varying forces, such as those of 

 sound-waves, by curves ; and emphatically lays down 

 that the ear is absolutely incapable of perceiving anything 

 more than can be expressed by such a curve. After giving 

 samples of undulatory curves corresponding to musical 



tones and to discordant sounds he makes the following 

 significant remark : " So soon therefore as it is possible, 

 at any place and in any manner, to set up vibrations 

 whose curves are like those of any given tone or com- 

 bination of tones, we shall then receive the same impres- 

 sion which the tone or combination of tones would have 

 produced upon us. Taking my stand upon the preceding 

 principles, I have succeeded in constructing an appar- 

 atus," &c. He concludes his paper by saying that the 

 newly invented phonautograph of Duhamel may perhaps 

 afford evidence as to the correctness of the views which 

 he has asserted respecting the correspondence between 

 sounds and their curves. 



The actual apparatus figured in this memoir and ex- 

 hibited to the Frankfort Society in October, 1861, is now 

 in my possession ; and I have also temporarily intrusted 

 to me a still earlier experimental telephone made by 

 Philipp Reis in the form of a model of the human ear. 1 

 This interesting instrument is depicted in its actual con- 

 dition and size in Figs. I, 2, and 3, and in section in 

 Fig. 4. It is carved in oak-wood. Of the tympanic 

 membrane only small fragments now exist. Against the 

 centre of the tympanum rested the lower end of a little 

 curved lever of platinum wire, which represented the 

 " hammer"-bone of the human ear.' This curved lever 

 was attached to the membrane by a minute drop of 

 sealing-wax, so that it moved in correspondence with 



every movement of the tympanum. It was pivoted near 

 its centre by being soldered to a short cross-wire serving 

 as an axis. The upper- end of the curved lever rented in 

 loose contact against the upper end of a vertical spring, 

 about I inch long, bearing at its summit a slender and 

 resilient strip of platinum foil. An adjusting screw served 

 to regulate the degree of contact between the vertical 

 spring and the curved lever. Conducting wires, by means 

 of which the current of electricity entered and left the 

 apparatus were affixed to screws in connection respec- 

 tively with the support of the pivoted lever and with the 

 vertical spring. 



If now any words or sounds of any kind were uttered in 

 front of the ear, the membrane was thereby set into 

 vibrations, as in the human ear. The little curved lever 

 took up these motions precisely as the "hammer "-bone 

 of the human ear does ; and, like the " hammer "-bone, 

 transferred them to that with which it was in contact. 

 The result was that the contact between the upper end of 

 the lever and the spring was caused to vary. With every 

 rarefaction of the air the membrane moved forward, and 

 the upper end of the little lever moved backward and 

 pressed more firmly than before against the spring, 



1 The property of M. Leon Gamier. Director of Garnier's Institute at 

 Fredrichsd .rf. near Homburg, where Philipp Reiss was formerly Teacher 

 of Natural Sciences. 



