MECHANICS OF THE INNER EAR 71 



This is the effect of our provisional assumption. But if the 

 partition tapers as it does, a unit of displaced fluid (corre- 

 sponding to a unit of stirrup movement) is made room for by- 

 sections of the partition of very unequal length according as 

 the displaced fluid unit is located nearer or farther from the 

 windows. Where the partition is narrow, a longer section 

 would have to move in order to make room for a unit of dis- 

 placed fluid. Where the partition is wider, a shorter section 

 would make room for the same quantity of fluid. 



Since, then, tone intensity depends on the length of the 

 partition section which is jerked up and down, and since this 



length is not proportional to the given 

 The computation value of the stirrup movement, it is use- 

 of a table ful to have a table showing the partition 



lengths corresponding to various stirrup 

 movements in order to get a clear idea of the influence of the 

 tapering of the partition upon the relative tone intensities. 

 To simplify the computation of such a table, it is well to 

 restrict it to a short distance from the windows, so that we 



U U ^x 



Fig. 25. The partition widens 



may approximately assume the partition to increase uni- 

 formly in width within this distance. Let us call w the 

 smallest width of the partition, near the windows; let us 

 assume that a distance from the windows equal to 50w the 

 width of the partition is 6w, and let us assume a uniform in- 

 crease of width. Let us call y the width at any point of the 

 partition and x the distance of this point from, the beginning 



