190 



ANIMAL MECHANICS. 



muscle of man, Fig. 35. Let 2O be the angle contained 

 between the extreme radiating fibres. Then, if I be the length 



of each fibre, 



and 



Fig. 35- 



Inherent Work = 2/Bl x 0. 

 Work done = 2/ SI sin 0. 



Work done 

 Inherent Work 



sin ( 



(33) 



In the great pectoral muscle of man, Fig. 35, a circle PQ, 

 described with a point 0 on the humerus as centre, coincides 

 appromixately with the origin of the fibres, ABCD; and 

 since the angle 20, contained between the extreme radiating 

 fibres, is 90 0 ; equation (33) becomes for the pectoral of man, 



Work done 

 Inherent Work 



sin 6 



'•9°°3- 



