Mr. T. H. Blakesley on Magnetic Lag. 37 



DB BC 

 CD DB-BC AB AB 



DA ABsinfl " Vl-cos 2 ^ 

 cose' y- 



Ca 3 H x /E*2 



VA ai Ba 2 m V A ai 



x/ 



- U"a 3 * 



A« 1 Ba 2 



Ca q Ba 9 



d m 2 



VA ai Ba 2 -CV 

 Thus the angle of magnetic lag, if it exist, can be detected 

 with two dynamometers and measured with three. 



In dealing yet further with the results furnished by the 

 observations, we must remember that the waxing magnetism 

 has the same inductive effect in producing E.M.F. in each 

 turn of the coils of the two circuits. But we can, from the 

 observation of dynamometer B, say what that E.M.F. per turn 

 is. The whole E.M.F. in the secondary coil is I 2 r 2 , conse- 

 quently the E.M.F. per turn is -^. Therefore in the primary 

 the total E.M.F. arising from magnetic induction is m - 2 — ^ 



772 _Lo Yo 



The current arising from the same source is l and the 



m 2 I r 2 n . Tl 

 magnetizing stress on this account is — 3 which must be 



looked upon as one of the components of the whole magneti- 

 zing stress due to the primary current ; and this component 

 is in the same phase as the magnetizing stress in the secondary. 

 Hence, returning to the figure, if we produce CB to F so 



that CB 



