378 



Dr. C. R. Alder Wright. 



[Jan. 28, 



a is found to correspond with the value A B = 25'9. In similar 

 fashion the values of C + C' are plotted off as ordinates to each of 

 the two sets of abscissae, and the ends of the two portions of curve 

 No. 2 thus obtained also joined, as shown by this dotted line. A 

 point, 6, is thus deduced where this dotted line cuts the perpendicular 

 to the base at the point a. .The length ab thus represents the value 

 of C + C' for the point a, i.e., at the " limiting point," when obviously 

 C = C' ; when the scale is sufficiently large this is found to correspond 

 with the value of C + C' = 83'5. From these two values for A B 

 and C + C' (= 2C), the following values for A, B, and C result: 



C = C' = ^ = 41-75 

 whence A + B = 100-41*75 = 58'25 

 A = A + B + ( A - B ) _ 58-25 + 25-9 _ 42 . Q7 



_ A + B-(A-B) _ 58-25-25-9 _ -, 6 . 18 



100-00 



By the second method. A, B, C, and A', B', C', having tne same 

 meanings as before, two curves are plotted, each with the values of 

 {A A' (B B')} 2 as abscissae, one with the values of A + .A' as 



