446 THE POPULAR SCIENCE MONTHLY. 



artist, are most often stamped witli a character of vague melancholy, from the 

 influence of which the mind cannot escape. It is especially when the noise of 

 the world is hushed that these powerful harmonies produce the most overpower- 

 ing and poetical effects." 



It characterizes, for example, the sound of the echo, the sound 

 called harmonics, and many others which are included in the range 

 of musical tones, defined further on under the name of chemical and 

 sympathetic music. We have the most remarkable examples of these 

 in the sound of the ^olian harp. Science, as well as philosojjhy, 

 poetry, and musical art, is interested in the further study of these 

 sounds. In Germany, Goethe and Novalis, in France, Jean Paul, 

 and many others, have eagerly appreciated the bond which unites 

 natural harmonies to the most elevated instincts, and to the most 

 ideal aspirations of the human soul. 



Prof. Tyndall has recognized the fact that, in order to render a 

 flame musical, it is necessary that its volume be such that it should 

 explode in unison with the undulations of the fundamental note of the 

 tube, or of one of its harmonics. He also asserts that, when the vol- 

 ume of the flame is too great, no sound is produced; he demonstrates 

 it, by increasing the flow of gas. Prof. Tyndall has also called atten- 

 tion to this fact, that, in order that a flame may sing with its maximum 

 of intensity, it is necessary that it should occupy a certain position in 

 the tube. He shows this by varying the length of the tube over the 

 flame, but he does not specify the proportions which must exist be- 

 tween the flame and the tube for obtaining this maximum intensity 

 of sound. M. Kastnei''s merit is in having shown that, when two or 

 several flames are introduced in a tube, they vibrate in unison, and 

 produce the musical maximum of sound wlien they are placed one- 

 third the length of the tube, and, if these two flames are brought in 

 contact, all sound ceases directly, a phenomenon M. Kastner demon- 

 strates to be caused by the interference of sounding flames. Here is 

 a question, lately scarcely thought of, of which M. Frederick Kastner 

 has determined the laws, at the same time making a most remarkable 

 application of them in creating an instrument which reminds one of, 

 and may be mistaken for, the sound of the human voice. 



A very simple mechanism causes each key to communicate with the 

 supply-pipes of the flames in the glass tubes. On pressing the keys the 

 flames separate, and the sound is produced (Fig. 1). As soon as the 

 fingers are removed from the keys the flames join, and the sound ceases 

 immediately (Fig. 2). These new experiments made by M. Kastner 

 upon singing-flames should cause all makers of musical instruments to 

 turn their attention to inventions connected with sound. If two flames 

 of suitable size be introduced into a glass tube, and if they be so dis- 

 posed that they reach one-third of the tube's height, measured from 

 the base, the flames will vibrate in unison. This phenomenon con- 

 tinues as long as the flames remain apart, but the sound ceases as 



