ANIMAL MECHANICS. 



359 



Let P denote the length of the equivalent fibre joining 

 0 and 0' situated in the two rectangular planes. In its 

 position of maximum effect, the perpendicular let fall upon 

 the line 00' from the intersection of the planes will be a 

 maximum, and will measure the work done ; wethus have 



p 



Maximum Work = — . 



For any other position of the fibre, making an angle 0 

 with one of the planes, it is easy to show that the perpen- 

 dicular, or 



p 



Work done = P sin 0 cos 9 = — sin 26. 



2 



Hence we have 



Work done 

 Maximum Work 



: sin 26. 



(108) 



We can thus calculate a Table showing the percentage of 

 the maximum theoretical work possible, which is actually 

 done by the observed muscle :-— 



Ratio of Observed Work done by Skeiv Iluscles to the Maximum 

 Possible Work. 



Muscle. 



Work done. 



Adductor secundus (/3). 



1. Llama, ...... 



2. " Master Magrath," . . 



Adductor secundus [a). 



99. 6% vex cent. 

 98.78* „ 

 99. 86 „ 

 97-13 „ 



99.98 



Mean, 



99.07S per cent. 



