THE PRINCIPLES OF MYODYNAMICS. 



53 



these components are brought to bear on the 

 joint-surfaces of the movable and fixed bones. 



40. The combined effects of the rectangular 

 components of the power and the weight on a 

 bony lever of any order may now be considered. 



(a) The following formulae may be noted in 

 regard to the three orders of the lever : 



I. p_j_Wzz=F .... (i.) 



II. P4_F=W .... (2.) 

 HI. F+W=P .... (3.) 

 In the above formulae : 



(i.) P is the resultant of the rectangular com- 

 ponents of \}^^ power. 



(ii.) W is the resultant of the rectangular 

 components of the weight. 



(iii.) F is the residtant of the rectangular com- 

 ponents of the fnlcrum. 



(b) In this place it may be remarked that the 

 rectangular components of the fulcrum may be 

 analyzed in the same manner as the rectangular 

 components of the power and the weight, in the 

 case of any order of bony lever. 



(c) In regard to the moving components of 

 the power and the resisting components of the 



