262 Prof. Rogers's Experiments on some Sonorous Flames. 



than that of the wick. The flame will then be seen to contract 

 and to lose much of its brilliancy, and will give forth a tone 

 which, with a little care, can be rendered quite smooth and con- 

 tinuous. 



These results are readily obtained with the flame of a small 

 circular-wicked lamp, now used in the United States for burning 

 the mixture of alcohol and turpentine. In this lamp the wick- 

 tubes rise about 2 inches above the reservoir, and an extei-nal 

 moveable tube is provided, which, being raised or lowered, serves 

 to vary the depth of the wick and to adjust the flame with great 

 nicety. The body of the lamp should be removed from its 

 pedestal and placed on a ring-support, to secure a free current 

 of air upward through the wick-tube. 



These results add but little to the beautiful experiments by 

 which Faraday, forty years ago, demonstrated the cause of these 

 musical vibrations ; but as they present some of the effects in a 

 more satisfactory form, they may give additional force to the 

 conclusion, that under proper conditions flames of every kind are 

 capable of exciting sonorous vibrations. 



I may here add, that my attention has lately been called to a 

 very striking effect of this kind, observed by Mr. W. F. Shaw, 

 an ingenious gas-fitter of Boston, while experimenting with the 

 wire-gauze burners which he uses in his gas-stoves. On invert- 

 ing one of these burners over the jet so as to bring the perforated 

 cylinder below, and the continuous metal tube above, the dia- 

 phragm of gauze (as seen in fig. 3), he found that the flame, 

 when duly adjusted, gave rise to a very powerful continuous 

 musical sound, which could be changed in pitch and loudness 

 by the addition of other pipes above. 



In this arrangement the gas becomes mingled throughout 

 with so large a proportion of air as probably to form a thoroughly 

 explosive mixture on the top of the wire-gauze, thereby favour- 

 ing the fullest development of the sonorous effect. 



In all these experiments the conditions are just such as are 

 suited to produce the succession of explosions which Professor 

 Faraday has shown to be the immediate cause of these musical 

 sounds. As regards the mechanical agency which renders the 

 explosions successive and not continuous, I think it is to be traced 

 to those vibrations which Savart has shown to belong to jets of 

 air, as well as of water and other liquids. 



That you may sec at a glance the conditions under which my 

 experiments have been made, I enclose a figure of my apparatus 

 for the sethcr-flame (fig. 1), one of the circular wick-lamps above 

 referred to (fig. 2), and also a figure of Shaw's burner in the 

 position in Mhich it gives the sonorous effect (fig. 3). 



The two former have been already described. The sether- 



