MECHANICS OF THE INNER EAR 89 



movement of the curve in figure 26. Let us disregard, how- 

 ever, the varying width of the partition, in order to avoid too 

 much compHcation. We shall again assume the partition to be 

 of uniform width, without, however, forgetting the fact that 

 this is an arbitrary simplification of the conditions. 



Imagine that the whole partition is in its normal posi- 

 tion, free of any stress, and that the stirrup begins an outward 

 movement of the form of the curve from E 

 The significance *° ^ ^" figure 26. We see from the curve 

 of a point of that the stirrup moves at first very slowly, 



inflection then gradually more and more quickly un- 



til at F, the point of inflection, it moves 

 with the greatest velocity. Now, a simple consideration will 

 make it plain to us that the pressure acting upon the initial part 

 of the partition must be dependent on, probably be propor- 

 tional to the velocity of the stirrup. If the velocity of the stir- 

 rup movement wiere extremely small, no point of the partition 

 would move more readily than any other, and consequently 

 none of them would move to a considerable extent; but the 

 fluid would every time and all the time flow through the 

 opening at the end of the tube which we called the safety 

 valve, because there would then be practically no friction at 

 any point within the tube, and an infinitesimal elastic force 

 of displacement could keep the partition in place. On the other 

 hand, if the velocity of the stirrup movement is not very 

 small, the points of the partition near the windows receive 

 the greatest push from the fluid, farther points only a slighter 

 push, very quickly diminishing with increasing distance, and 

 at some distance away the push could be regarded as practi- 

 cally infinitesimal ; all this as the result of the friction of the 

 fluid in the narrow tube, the total influence of which is the greater 

 the longer the column of fluid in question, measuring this column 

 from the windows. 



