178 ALEXANDER GRAHAM BELL 



modeled still more closely upon the mechanism of the human 

 ear, and for this purpose I sought the assistance of a distin- 

 guished aurist in Boston, Dr. Clarence J. Blake. He sug- 

 gested the use of the human ear itself as a phonautograph, in- 

 stead of making an artificial imitation of it. The idea was 

 novel and struck me accordingly, and I requested my friend 

 to prepare a specimen for me, which he did. The stapes was 

 removed and a stylus of hay about an inch in length was 

 attached to the end of the incus. Upon moistening the 

 membrana tympani and the ossiculse with a mixture of gly- 

 cerine and water the necessary mobility of the parts was ob- 

 tained, and upon singing into the external artificial ear the 

 piece of hay was thrown into vibration, and tracings were ob- 

 tained upon a plane surface of smoked glass passed rapidly 

 underneath. While engaged in these experiments, I was 

 struck with the remarkable disproportion in weight between 

 the membrane and the bones that were vibrated by it. It 

 occurred to me that if a membrane as thin as tissue paper 

 could control the vibration of bones that were, compared to 

 it, of immense size and weight, why should not a larger and 

 thicker membrane be able to vibrate a piece of iron in front 

 of an electromagnet, in which case the complication of steel 

 rods shown in my first form of telephone could be done away 

 with, and a simple piece of iron attached to a membrane be 

 placed at either end of the telegraphic circuit. 



The form of apparatus that I was then employing for 

 producing undulatory currents of electricity for the purpose of 

 multiple telegraphy consists of a steel reed, clamped firmly 

 by one extremity to the uncovered leg of an electromagnet, 

 and the free end of the reed projected above the covered leg. 

 When the reed was vibrated in any mechanical way the bat- 

 tery current was thrown into waves, and electrical undula- 

 tions traversed the circuit, throwing into vibration the corre- 

 sponding reed at the other end of the circuit. I immediately 

 proceeded to put my new idea to the test of practical experi- 

 ment, and for this purpose I attached the reed loosely by one 

 extremity to the uncovered pole of the magnet, and fastened 

 the other extremity to the center of a stretched membrane of 

 gold beaters' skin. I presumed that upon speaking in the 



