370 NOTE TO ART. 124. [APPENDIX. 



= 2H- (10 + 15n + 3rc t )& + (2 +ri)ff I, 





^ I, 

 I, 



JP 



2H 



in which k=j> Z=AB=CD, nl = ~BC and H = 4 + 8n + 3n*. 



We have first to put these formulas into the most convenient 

 shape for use in the particular case under consideration. Thus 



1 OK 



in this case I 40, n I = 20 ; hence n = - and H = , and 



a 4 



k = , where a has the successive values of 10, 20, 30, 40 for P,, 

 40 



123 4 

 P,, P,, P 4 . Tc is therefore successively -, -, - and -. 



Our equations for reactions are then, after reducing, 



5 r 'i 



RA ~35(_ 7 ~ 73 + 10 J' 



35 



1. 



Now, as we may notice, the denominator of k is always 4, of 

 If always 64 ; the numerator only changing according to the 

 position of the weight. These equations can then be written 



_5_ 



224 



R B _ R = 



Hn = ^TT: I 5 a 8 136 a 



where a has the values 1, 2, 3 for P^ P 2 , P 3 , etc. 



These, then, are the practical formulae for this case, and from 



