MECHANICS OF THE INNER EAR 1 I 



thirty units inwards, pushing down successively all the thirty 

 sections of the initial part of the partition. We find, therefore, 

 in figure 13 at B all the thirty sections at their lower limits. 

 From B to C, the stirrup makes an outward movement through 

 nineteen spaces. The result is an upward movement of an 

 equal number of sections of the partition. We find, therefore, 

 at C the first nineteen sections of the partition at their upper 

 limits. All the following parts of the partition remain ex- 

 actly in the positions at which they were at the time B, since — 

 according to the assumptions under which we are working — 

 no force whatsover has acted upon them. That is, the sec- 

 tions twenty to thirty are still at the lower limits, and the 

 further parts of the partition in their normal positions. From 

 C to D the stirrup moves inward through six spaces, as seen 

 in figure 11. It causes therefore the first six sections of the 

 partition to be jerked down. In this position we find them 

 in figure 13 at D. All the rest of the partition remains exactly 

 as it was at C. That is, the next thirteen sections are still 

 at the upper limits and the following eleven still at the lower 

 limits where we found them at B. From D to E, the stirrup 

 makes an outward movement through six spaces, causing an 

 equal number of the initial sections of the partition to be jerked 

 up. We therefore find in the figure at E the first nineteen sec- 

 tions of the partition at the upper limits, the following eleven 

 at the lower limits. From E to F, the stirrup moves inward 

 again through nineteen spaces, causing nineteen sections of 

 the partition to be jerked down. We find, therefore, in the 

 figure at F all the thirty moving sections of the partition at 

 the lower limits. From F to G, the stirrup moves outward 

 through thirty spaces, as seen in figure 11. This causes thirty 

 sections of the partition to be jerked up. So we find in figure 

 13 at G the whole initial piece of the partition which moves 

 and therefore alone concerns us, at the upper limit. The stir- 

 rup has now reached the very position from which it started 



