ACOUSTICAL INVESTIGATION OF THE JAPANESE BAMBOO PIPE. 33 



the pipe plays an important part in the production of the note. 

 Indeed, for overtones, the distance between the lower end and 

 the holes approaches the half wave lengths of the notes, so 

 that the lower part may form a resonator whose pitch is near 

 that of the upper part. Thus the pipe, as a whole, forms a 

 communicating system of two resonators. The complete explana- 

 tion of the phenomena may, therefore, be made only after the 

 investigation of such a multiple system of resonators, has been 

 fully made. However, a qualitative explanation is possible for 

 a number of cases, as in the following. 



In position No. 5, the virtual length of the pipe above the 

 open hole is nearly equal to the whole wave length of the note 

 aT while the lower half is a little longer than the half wave 

 length of the same note. Therefore, for this note, the vibration 

 of the air takes place within the pipe in such a way that very 

 near the open hole an actual loop is produced and only a small 

 portion of the energy escapes from the lateral opening. This is 

 verified by the experiment, since if the open hole be closed 

 while the pipe is being blown, the general mode of the vibra- 

 tion remains nearly unaltered, only the pitch is slightly lowered. 

 Indeed, of corresponds nearly to the second overtone of 

 position No. 1. In a similar way, in the first overtones for the 

 positions Nos. 18, 19, 20, 28, 24, 25, etc., the back hole 

 aj^proximately corresponds to the loop of the third overtone Of 

 the position No. 1. Therefore, for these positions in which 

 holes near the nodes of that mode are closed, this note is liable 

 to be produced. 



In position 17, the fundamental tone is very high if com- 

 pared with others such as Nos. 18, 19, etc. In this position, 

 no energy escapes from the back hole, so that there is no change 



