ANIMAL MECHANICS. 



341 



Hence we see, by a process of reasoning similar to that 

 employed in reference to the great pectoral muscle of the 

 wing of the bird, that the axis of maximum instability corre- 

 sponds to X => - 0.0085, an( ^ tnat tne ax i 9 °f maximum sta- 

 bility corresponds to X = + 29.3. 



I K A 



l' 



Fig. 90. 



The value of X corresponding to the axis of maximum 

 instability is so nearly zero, that we may assume X = o, without 



sensible error. This value of X corresponds with X' = ^, so 



that the equations (81) of the planes passing through the 

 bones are reduced to 



y - mx = o, 



(102) 



% + c =0. 



The corresponding axis of rotation is shown in Fig. 90, 



