Prof. A. M. Mayer's Researches in Acoustics. 



355 



tions of the residual sonorous sensations, making use, under my 

 directions, of the same apparatus which I employed in my ori- 

 ginal experiments. Madame Seiler in former years worked much 

 with Helmholtz, assisting him with her fine ear in experiments 

 contained in his renowned work Die Lehre von den Tonempfin- 

 dungen. This lady unites to educated musical perceptions a 

 knowledge and appreciation of recent advances in physiological 

 acoustics ; and hence I have great confidence in the determina- 

 tions made by her. These results [ give in the following Table, 

 which I desire to take the place of that published in my paper 

 of October 1874. 



Golumn S of this Table contains the simple sounds experi- 

 mented on; they are designated in the notation stamped by 

 Konig on his forks. Column N gives the number of vibrations* 

 per second corresponding to the sounds of column S. In column 

 D are the corresponding durations of the residual sensations, 

 expressed in vulgar and in decimal fractions. The reciprocal of 

 the number of beats per second required to produce a continuous 

 sensation by a given sound is taken as the duration of the resi- 

 dual sensation of this sound f. In column L are given the num- 

 ber of wave-lengths contained in the separate impulses into 

 which the sound had been divided in order to produce the con- 

 tinuous sensation. 



s. 



N. 



D. 



L. 



ut r 



64 



■i-s =-0395 sec. 



2-5 



Ut 2 . 



128 



^=•0222 „ 



2-8 



ut 3 . 



256 



^='0142 „ 



36 



sol 3 . 



384 



Tfe='0098 „ 



37 



ut 4 . 



512 



T^o = W6 „ 



3-9 



Mi 4 . 



640 



-^=•0065 „ 



4-1 



Sol 4 . 



768 



Th = -0060 „ 



4-6 



Ut 5 . 



1024 



t!o = -0055 „ 



5-6 



Although at first sight the apparatus which I have used in 

 this research may appear coarse, yet experience showed that the 

 accuracy of a determination dep ended more on the ear than on 



* I here, as always, refer to complete vibrations, i. e. to a motion to and 

 fro, or to what the late Professor J3e Morgan proposed to call a swing-, 

 swang. 



t That is to say, we take as the duration of the residual sensation 

 the interval during which the impress of a beat has not diminished suffici- 

 ently in intensity to cause discontinuity in the sensation. To obtain the 

 duration of the entire sensation, we should have to know the intensity of 

 the sensation at the end of the above interval, and the law giving the rate 

 of diminution of the sensation. 



