A. M. Mayer — Researches in Acoustics. 



vibrations which pass the disk with increasing intensity, from 

 to 4, fig. 5, and with decreasing intensity from 8 to 12. 



In our experiments we measured the number of flashes of 

 sound entering the ear by knowing the number of revolutions 

 of the disk per second and the number of holes in the disk. 

 From this knowledge we compute the time it took the disk to 

 go over I) to E, in fig. 6. the distance between centers of two 

 neighboring holes ; then we reduced this time by -§- which is 

 the ratio of the diameter of the opening in the nipple of 

 resonator to the distance, D to E, and took this reduced time 

 as the duration of the uniform residual sensation. The dura- 

 tion of the sonorous sensation determined in this manner is 

 evidently nearer the truth than that obtained with apparatus 

 in which the hole in the tube conveying the sound to the disk 

 and the holes in the disk have the same diameter. 



Fig. 1. 



The Apparatus and Methods used to measure the durations 

 of residual sonorous sensations. — (A) I shall first describe the 

 apparatus which I found the most efficient for these measures 



