ACOUSTICAL INVESTIGATION OF THE JAPANESE BAMBOO PIPE. 23 



were carried out. The eyliiulrical glass pipe used in the pre- 

 vious experiment for the effect of the aperture of 

 the embouchure was fixed horizontally. The 

 length of the air column inside the pipe was 

 adjusted by means of a wooden piston around 

 wliicli a sheet of cloth was wound so that it 

 fitted tightly to the inside of the pipe. Dia- 

 phragms were made of wooden cylinders of 

 different lengths bored with cylindrical or conical 

 passages of diflerent calibres. Their lateral sides 

 were covered by velvet in order to secure close 

 contact with the interior of the ghiss pipe. Each 

 of them was placed in the resonator successively 

 at difterent distances from the open end. The tuning forks of 

 the series used in the previous experiments, were successively 

 l)rought near the open end and the lengths of the tube giving 

 tlie maximum resonance were determined. 



First, the diaphragms with cylindrical passages of different 

 diameters, were tested. The results of the experiments are given 

 in Figs. 8, 1), and 10 in full lines, in which the abscissa is the 

 distance of the middle section of the diaphragm from the open 

 end, and the ordinate is the length of the air column measured 

 from the open end to the piston. Horizontal dotted lints show 

 the length of maximum resonance when no diaphragm is present. 

 The difference of the ordinate between a curve in full line and 

 the corresponding horizontal dotted line gives the correction of 

 the length due to the corresponding combination of the diaphragm 

 and the tunins; fork. It will be remarked : 



a) That the curves for different notes are nearly parallel ; 



b) The the correction is negative when the diaphragm is 



