

1'Al ;IIAM OF 



/' and 7? will chanirr; but bott equation 



'rcewe adopt. it t'"ll.\vs that tin- 

 function f /'. ./ must be of tli** t-Tin /'<!> ./ . H.-nn- we have 



sent the position of the pa; 



s of the equal forces 

 .!//> the direction of the 



tant P 



.I/'/. Mil. .I//:, making the I 



fries ('MA. f/.l/.l. //.I///, /;.!/// all 

 equal, and let z denote the magnitude 

 ot each angle. Suppose the t '<, / 



.g along MA to be resolved 

 two equal forces acting alon-_ r M f< 

 and M<> ively; denote each 



of these components by Q; then 



' 



l; solve P noting alonir M/t in like manner into t\vo 



] \ equal to ft. acting along J/A' and Mil \> 

 . Thus the two fon^s P are replaced by the four 

 - V all<l conaequentiy tlie resultant of these four ; 



icide in magnitude and direction with the resultant // 

 of the two forces P. 



i"iiote the resultant of the t\vo forre* 0, acting along 

 MQ and J///; since <;MD = 7/.l//> = a: - z, we have 



'/7> is the direction ot 



Similarly, tl 'rant Q" of t] ' will act 



along MD ; and since CMD = EMI) = x - 



O' and (f 1-ntli act. alonir the straight line .!//>. their 

 resultant, which is a!^. the r sultant ot tlie t-ur l-r. -.-< V. must 

 be equal to their sum ; hence 



But we have P<f> (x) - Q</> (z) <f> (x). 



ce . +(x) +(z) =</>( + z) +<f>(x-z) 



(1). 



