"After the telegraphic marvels which can repro- 

 duce at a distance handwritings, or even more or less 

 complicated drawings, it may appear impossible to 

 penetrate further into the regions of the marvelous. Yet 

 we will try to advance a few steps further. I have, for 

 example, asked myself whether speech itself may not 

 be transmitted by electricity in a word, if what is 

 spoken in Vienna may not be heard in Paris. The thing 

 is practicable in this way: 



"We know that sounds are made by vibrations, and 

 adapted to the ear by the same vibrations which are 

 reproduced by the intervening medium. But the in- 

 tensity of the vibrations diminishes very rapidly with 

 the distance ; so that it is, even with the aid of speaking- 

 tubes and trumpets, impossible to exceed somewhat 

 narrow limits. Suppose that a man speaks near a 

 movable disk, sufficiently flexible to lose none of the 

 vibrations of the voice, and that this disk alternately 

 makes and breaks the currents from a battery : you may 

 have at a distance another disk, which will simultane- 

 ously execute the same vibrations. 



"it is true that the intensity of the sounds produced by 

 means of the voice at the point of departure where the 

 first disk vibrates will be variable and will be constant 

 at the point of arrival, where the other disk vibrates by 

 means of electricity; but it has been shown that this 

 does not change the sounds. It is, moreover, evident 

 that the sounds will be reproduced at the same pitch." 



Here was the correct conception, theoretically, at 

 least, of a practical telephone. But Bourseul did not 



[7*] 



