THE PHONOGRAPH, OR VOICE-RECORDER. 285 



obtained an imitation only requiring, to render it perfect, 

 as I have myself experimentally verified, attention to the 

 consideration respecting liquids pointed out in the preceding 

 paragraph. " Here," says Tyndall, describing the experiment 

 as conducted during a lecture, "is a free reed fixed in a 

 frame, but without any pipe associated with it, mounted on 

 the acoustic bellows. When air is urged through the orifice, 

 it speaks in this forcible manner. I now fix upon the frame 

 of the reed a pyramidal pipe ; you notice a change in the 

 clang, and, by pushing my flat hand over the open end of 

 the pipe, the similarity between the sounds produced and 

 those of the human voice is unmistakable. Holding the 

 palm of my hand over the end of the pipe, so as to close it 

 altogether, and then raising my hand twice in quick succes- 

 sion, the word ' mamma ' is heard as plainly as if it were 

 uttered by an infant For this pyramidal tube I now 

 substitute a shorter one, and with it make the same 

 experiment The ' mamma ' now heard is exactly such as 

 would be uttered by a child with a stopped nose. Thus, by 

 associating with a vibrating reed a suitable pipe, we can 

 impart to the sound of the reed the qualities of the human 

 voice." The " m " obtained in these experiments was, how- 

 ever, imperfect To produce an "m" sound such as an 

 adult would utter without a "stopped nose," all that is 

 necessary is to make a small opening (experiment readily 

 determines the proper size and position) in the side of the 

 pyramidal pipe, so that, as in the natural utterance of this 

 liquid, the emission of air is not altogether interrupted. 



I witnessed in 1874 some curious illustrations of the 

 artificial production of vocal sounds, at the Stevens Institute, 

 Hoboken, N.J., where the ingenious Professor Mayer (who 

 will have, I trust, a good deal to say about the scientific 

 significance of telephonic and phonographic experiments 

 before long) has acoustic apparatus, including several 

 talking-pipes. By suitably moving his hand on the top of 

 some of these pipes, he could make them speak certain words 

 with tolerable distinctness, and even utter short sentences. 



