THE PHONOGRAPH, OR VOICE-RECORDER, 275 



description of the practical effect of details of instrumental 

 construction, and the like for only he who is in the habit 

 of using special instruments or classes of instrument can be 

 expected to be competent adequately to discuss such matters. 



Although, however, the phonograph is not an instrument 

 depending, like the telephone, on the action of electricity 

 (in some form or other), yet it is related closely enough to 

 the telephone to make the mistake of the Telegraphic 

 journalist a natural one. At least, the mistake would be 

 natural enough for any one but a telegraphic specialist ; the 

 more so that Mr. Edison is a telegraphist, and that he has 

 effected several important and interesting inventions in tele- 

 graphic and electrical science. For instance, in the pre- 

 vious article, pp. 270, 271, I had occasion to describe at 

 some length the principles of his " Holograph." I spoke 

 of it as " another form of telephone, surpassing Gray's 

 and La GOUT'S in some respects as a conveyer of musical 

 tones, but as yet unable to speak like Bell's .... in 

 telegraphic communication." I proceeded : " Gray's tele- 

 phone is limited to about one octave. Edison's extends 

 from the deepest bass notes to the highest notes of the 

 human voice, which, when magnets are employed, are almost 

 inaudible ; but it has yet to learn to speak." 



The phonograph is an instrument which has learned to 

 speak, though it does not speak at a distance like the tele- 

 phone or the motograph. Yet there seems no special reason 

 why it should not combine both qualities the power of 

 repeating messages at considerable intervals of time after 

 they were originally spoken, and the power of transmitting 

 them to great distances. 



I have said that the phonograph is an instrument closely 

 related to the telephone. If we consider this feature of the 

 instrument attentively, we shall be led to the clearer recog 

 nition of the acoustical principles on which its properties 

 depend, and also of the nature of some of the interesting 

 acoustical problems on which light seems likely to be thrown 

 by means of experiments with this instrument. 



