SKETCH OF ELISHA GRAY. 527 



construction of the speaking telephone of to-day. When used in con- 

 nection with his articulating transmitter, which was developed at a 

 later date, articulate words have been received upon it ; and when a 

 duplicate of the instrument is inserted in a closed circuit, which includes 

 a galvanic battery, it becomes a speaking telephone capable of acting 

 both as a transmitter and as a receiver. Mr. Gray did not know at 

 that time, however, that he could use it as a transmitter, although he 

 had fully demonstrated its ability to receive sounds of varying quality. 

 At that date his conception of a transmitter for the transmission of ar- 

 ticulate words was a mechanism which would employ such tones as were 

 needed, and would enable one to manipulate them in whatever manner 

 was requisite to produce the desired effect. In other words, he sup- 

 posed it would be necessary to construct a mechanism similar to the 

 vocal orsrans of the throat, which would mold electrical waves into the 

 same form that the air is molded when a spoken word is uttered. This 

 seemed too complicated a machine to be easily constructed ; hence he 

 determined to experiment particularly in the direction of the more per- 

 fect transmission of composite tones, so that each individual tone would 

 have its individuality and place properly preserved in the clang of 

 which it was a part ; and to the analysis of the same at the receiving 

 end, so that any particular tone would respond upon one instrument, 

 and one only. This general result once attained, it was his purpose to 

 make an application of it to multiple, printing, and autographic teleg- 

 raphy. While engaged in these experiments he was continually on 

 the alert for developments that might assist him to solve the inter- 

 esting problem already before his mind, that of transmitting spoken 

 words. Shortly after he constructed a transmitter, consisting of a re- 

 volving shaft, upon which were mounted two eccentric cams, having one 

 or more projections. These actuated two small levers, causing them to 

 vibrate upon their respective break-points, through whicli points a bat- 

 tery current passed. He employed, in connection with this transmit- 

 ter, a receiver which was adapted to the reception of all varieties of 

 sounds. 



When this apparatus was put in operation a sound of peculiar qual- 

 ity, not unlike that of the human voice when in great distress, proceeded 

 from the receiver. By altering the tension of the spring in various 

 ways he was able to imitate many different sounds involving the vow- 

 els only, and succeeded, among other things, in producing a groan with 

 all its inflections in the greatest perfection. Up to the time of making 

 this experiment Mr. Gray had associated in his mind, in connection with 

 transmission of spoken words, a complicated mechanism. This experi- 

 ment produced an entire change in his views, and he came to the con- 

 clusion that in solving the problem of transmitting spoken words it was 

 not necessary to consider the mechanism of the vocal organs at all, but 

 simply the physical results produced in the atmosphere by them, and 

 all that was necessary, therefore, was to devise a transmitter that would 



