MECHANICS OF THE INNER EAR 95 



riod, and that the nerve ends located there receive only one 

 shock during the period. The third section has an extreme 

 upward position at F, a medium upward position at G:=A and 

 also at B, a medium downward position at C, D, and E. The 

 nerve ends of this section receive therefore one shock during 

 the period. The fourth section has a medium upward position 

 at G=A and at B, a medium downward position at C, D, E, and 

 F. The nerve ends of this section receive therefore one shock 

 during the period. It is plain, then, that from our theory we 

 must expect to hear the tone 2 as well as the tone 1, the former 

 conveyed by the first, the latter by the three following sec- 

 tions of the partition. 



To determine the relative intensities of the tones heard, 

 we have to compare the length of the initial section of the par- 

 tition with the total length of the three 

 Sixth provision- following sections when added together. 

 al assumption For simplicity's sake, let us make this 



comparison again under the third and 

 fourth provisional assumptions, and also under a new assump- 

 tion, namely, that the fluid for which room is made or whose 

 room is taken by a move of the partition from a medium to an 

 extreme (or the reverse) displacement on the same side (eith- 

 er above or below the normal position) is a negligible quanti- 

 ty. That this assumption simplifies our representation of the 

 successive positions of the several sections of the partition is 

 clear, since we may thus take the length of each section pro- 

 portional to the ordinate difference of the corresponding points 

 of the curve. For instance, the third and fourth sections in 

 figure 29, which move down at C, would be longer than pro- 

 portional to the ordinate difference of the points B and C in 

 figure 26 if the fluid displaced by the first and second sections 

 in moving from an extreme position at B to a medium displace- 

 ment at C were not a negligible quantity. In the latter case, 

 the fluid displaced by the first and second sections during the 



