( H. I THE IN'Dt'Cl 19 



is practically constant for all runvnts in tin- armature, 

 u In!-- in others W is percept i I >!\ diminished as the ai mature 

 cunvnt i^ increased. 



:.ermi.-nU were made on the arc light dynamo. 

 previously descri lied, to ascertain the amount of the reduc- 

 tion of M doe to this cause. The current in the ma 

 was kept constant at '.' ani)K>re8, and tin* annaturr c-urn-nl 

 increased from iu>thit)L r to 1" amperes. Th- induction 

 factor was obsen*el \>\ th<- tonpic m.-thinl. Th<- n-sult- 

 are |.!..tr,-,l in Fi^. '.'. M decreases from 70 to 63. 



The f\|K'riiiitiit mad- mi the Kdi-"n 1J K.\V. duianm 

 and pl)tt-il in I'l^ | shows no change in the value <>f U 

 due to this cause. This matt, r will \te discussed in greater 

 detail in a later chapter under the name of Armature 

 Reaction. 



r 2 



