112 



Dr. R. Konig on Manometric Flames. 



single tube to act on a capsule, I place a small apparatus to both 

 exits of the two tube-branches ; this is so arranged that now 



Fig. 13. 



each branch is in communication with a separate capsule. These 

 two capsules, whose action on each other is annulled by two ac- 

 cessory capsules, are provided with two gas-pipes instead of one. 

 On a stand are placed three burners, which are fixed at different 

 elevations ; the centre one is arranged for the reception of two 

 india-rubber tubes. I connect now one gas-pipe of the one cap- 

 sule with the highest burner, one pipe of the other capsule with 

 the lowest, and by means of the remaining two exit-pipes I place 

 both capsules in communication with the centre burner. If I 

 now strike the tuning-forks while the lengths of the tube-branches 

 are equal, the three flames in the rotating mirror show, three 

 equally deeply serrated flame-series one above another, of which 

 the centre alone changes into a simple band of light on length- 

 ening one of the branches a half wave-length of the note, while 

 both the other flames continue to vibrate with unchanged inten- 

 sity. Thus we have here at the same time a view of the action 

 of the sound-waves when they approach through the one arm 

 alone, when they have passed through the second only, and 

 also when they arrive united at the flame after passing through 

 both. 



If in these experiments we employ instead of a tuning-fork 



