( 426 ) 



Differences 

 of intensities. 



10% 



six 



sol 



Gl 

 61 



zz 



^ -J 1.^1. Zr^Z. 3.^3. W<(. s.^9. 6r>^é, 



Smallest perceptible difference of intensity by the scale. 



CONCLUSION. 



1. From the results of the experiments with the tuning-fork 

 proceeds that the law ofWp^BER is valuable, when taken in a general 

 way, but not exactly for the investigated middle-strong and weak 

 intensities. 



2. From the results of the organ -pipes proceeds that the most 

 favourable "Unterschiedsschwelle" is found with c* and that from 

 there to the ends the power of distinguishing differences in intensities 

 decreases rather regularly. 



ERRATUM, 

 p. 380 line 7 for 0,990 i,03 read J ,02 1,04. 



(November 22, 1905). 



