ANIMAL MECHANICS. 



Hence, equations (105) and (107) give 



353 



L' 



— - + 0.196, 

 but 



P 2 = L 2 + L 2 - 2LL' cos 20 + 4c 2 , 



from which we find, by eliminating L and L\ and using the 

 constants of the hyperboloid, 



2c = 2.38, 2(j> = 49° 15', 



and 



L = + 1.010 in., L' = + 5.167 in. 



On laying down the points 0 and 0', just found, upon the 

 pelvis and femur, and measuring their distances from the 

 centre of the socket of the hip joint, I found — 



Distance from 0 to centre of socket = 2.88 in. 

 Distance from 0' to centre of socket = 3.14 ,, 



Difference, . . 0.26 in. 



The points 0 and O' both lie within the origin and inser- 

 tion ; but it is to be noticed that the point 0' is brought down 

 to the near end of the insertion on the femur, within 0.56 in. 

 of its extremity. We may also remark that the equivalent 

 fibre, 00', does not coincide in direction with any of the real 

 fibres of the muscle, none of which intersect each other in 

 space. 



2 A 



