106 Dr. R. Konig on Manometric Flames. 



vibrate only when its particular resonator is put in action by a 

 note in unison ; the notes not contained in the series of reso- 

 nators must have no effect whatever on any of the names. In 

 order to show how far the apparatus fulfils these conditions, I 

 usually employ a series of tuning-forks on sounding-chests, 

 which, particularly a few moments after being sounded, give 

 almost simple notes. 



I first take forks which are in tune with the resonators, and 

 sound them singly, and show that only the bands of light which 

 correspond to their notes dissolve into vibrations, so that several 

 simple notes must be sounded to cause the appearance of several 

 serrated bands of light. By means of a tuning-fork not in tune 

 with the resonators, I can then show that its note, even when 

 sounded with considerable force, has no effect on the flames. A 

 note sounded with very great intensity may indeed have some effect 

 on all the flames, through the resonators ; but this case will not 

 give rise to error, as all the flame-series appear equal, whereas, 

 when resonance takes place, the number of the single flame- 

 waves in the series increases upwards in the proportion of 1 : 2 : 3 

 &c, and their width, of course, decreases in the inverse ratio. 



After demonstrating in this way the nature of the apparatus, 

 I produce before it a sound whose fundamental is c ; and the ser- 

 rated bands of light then show by what harmonic notes the fun- 

 damental is accompanied, as well as the relative intensities of 

 these notes. If before the apparatus we play the g of the violin, 

 for which the apparatus has no resonator, the octave g vibrates 

 strongly, and the c of the same instrument resolves, together 



with the flame of the fundamental, that of the octave c. An 

 open organ-pipe, of small diameter, tuned to c, when forcibly 

 blown, set the first five flames in vibration, but the third vibrated 

 more strongly than the octave. A closed organ-pipe with the 

 same fundamental caused the twelfth to appear very strong, and 

 the fifth very weak. A protruding tongue without a sounding- 

 cup resolved the first six harmonic notes with pretty regularly 

 decreasing intensity. 



On singing the vowel U, the octave as well as the fundamental 

 shows rather strong vibrations, and only sometimes a trifling 

 effect may be observed on the third note. D, on the contrary, 

 excites the flames of the third and fourth notes very strongly, 

 while the vibrations of the octave are weaker than with U. The 

 fifth flame- band is serrated, but slightly, with 0. With OA 

 the region of greatest intensity becomes higher ; it is the fourth 

 and fifth notes which show the deepest indentations in the band 

 of light, while the lower notes are weaker. With A all the flames 

 are resolved up to the seventh, and the fourth, fifth, and sixth 



