Power by Uynamo-electrical Machines. 523 



§ 3. Comparison of the Values of the Work. 



After having obtained a definite expression for the current- 

 strength iy the expressions for 1\ and T 2 given in (III.) and 

 (V.) are completely defined, so that they may serve for calcu- 

 lating these two magnitudes. 



In order to make the formulae more adapted for comparison , 

 we wall introduce a simple sign for the member affected by the 

 small factors a and X by putting 



f-QV'M (l3) 



The two equations then become 



fr-( («+W+i J***)* • • • (14) 



T »" ((.+txt-K) y> ~ 7< ) ft • • • (15) 



Moreover from (5), 

 ' e+ . ^ +P (v 1+ v 2 ) + (, + ^ r ^ 1+ vl) 



(a + i)(b + i) P v l —v 2 



We will here again introduce an abbreviated symbol by 

 putting 



8=p(v 1 + v 2 )+(a+^)(vl + v% . . (16) 

 by which the expression changes into 



iP=Z — r ( 17 ) 



(a + i)(6 + i) ^1—^2* 



By using this equation we can put the above two equations 

 for Ti and T 2 in the form 



T i=[( R + S )~^ 2 +^]^ • • • (18) 



T 2 =[(R + S)-5-- y ^ , . . (19) 



Subtracting these equations from one another, we have 



T 1 -T 2 =[R + 8 + 7 (^ + ^)]i 2 . . . . (20) 



