10 Dr. R. Konig on Manometric Flames, 



ordinary height at c, as though it had been produced by the 

 vibrations of an organ-pipe provided with a capsule at the node. 



The note d also showed a series of high and sharply defined 

 flames, which, however, quite disappeared at e to give place to 

 the weak rounded-off waving lines as far as a. 



This sudden appearance of very high flames in the region of 

 c~is explained by the circumstance that the lowest proper note 

 of the interior air of the violin is precisely c. For the upper 

 notes I obtained the same result as with the stethoscope ; that 

 is to say, the notes a and b again gave much stronger vibra- 

 tions than e f g, and than the upper c d e &c; so that the 

 second peculiar note of the interior air, or rather of the whole 

 system formed by the violin, seems to be in the region of a and b. 



With regard to sound, we have in this case certainly been able 

 only to make evident the transition from the figure of the octave 

 to that of the simple note. The siren shows much better the 

 gradual disappearance of the higher upper note from the musical 

 sounds when their fundamental tone is raised. To this end I 

 intercept the impulse above the open perforated plate by means 

 of an arched aperture which expands into a small tube, and is 

 placed immediately above a part of the apertures so as to permit 

 them to affect the flame, while I cause the rotation of the plate to 

 increase from its lowest to its highest swiftness by increased pres- 

 sure of the air. The mirror then shows at the lowest notes very 

 large and dense flame-groups; these change towards the middle 

 of the great octave into more clearly defined and deep-slit waves, 

 with at first five, then towards c and d with four flame- points. 

 At g and a the number of the points falls to three, at c and d 

 to two; and at a the last trace of the octave disappears from the 

 sound; after this all the still higher notes only show single 

 flame-pictures. 



But the result of this experiment is essentially different if when 

 a sounding-chest is fastened over the perforated plate. It first 

 intensifies the upper harmonics of the sound, then the lower, and 

 lastly the fundamental itself: this causes the flame-groups no 

 longer to become simpler gradually and in accordance with the 

 height of the notes, but to show rather sudden changes alter- 

 nately rising and disappearing. Thus the sound of a siren, 

 over the perforated plate of which a resonance-box giving the 



note c was placed, after showing a few complicated and faint 

 pictures when the plate was slowly rotated, produced on reach- 

 ing the pitch c clearly a large flame in agreement with the fun- 

 damental tone : this flame had four summits, derived from 



