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C. Bancs — Combination Tones of the 



Art. XIII. — The Combination Tones of the Siren and an 

 Organ Pipe ; by Carl Barus. 



In view of the brilliant development of experimental acous- 

 tics, I can hardly suppose that the present simple but efficient 

 method of studying combination tones (difference tones in par- 

 ticular) is new. Be this as it may, the subject on its own 

 merits is well worthy of close inspection, and the chart which 

 I submit will, I think, be of much assistance. Without it, the 

 disentanglement of the interpenetrating trains of harmony 

 which reach the listener, is extremely difficult even to a musical 

 ear. I will therefore venture to describe my work. 



7$ U 75 76 



Helmholtz in his classical experiments obtained his most pro- 

 nounced combination tones by the aid of his many-voiced siren. 

 Few, however, possess this apparatus. Moreover, in the case 

 given, the difference tones must change from low to high pitch. 



