94 



effected by the self-induction of the 

 armature; but Mr. Kennedy states that 

 the difference in exciting-power for full 

 output and running idle is not great. 

 From analogy, with his own machines, 

 the author estimates that the induced 

 electromotive force of this machine, when 

 giving 150 volts at the terminals, would 

 be about 165 volts. If the armature were 

 coupled to give a continuous current, the 

 electromotive force produced by a field 

 of 148 lines would be 154, so that k in 

 this machine must be about 1.07. This 

 value, although rather smaller than 

 theory would indicate, is yet within the 

 limits given above. It may here be 

 mentioned that Mr. Kennedy advocates 

 the use of low-pressure alternators in 

 connection with step-up transformers if 

 a high-pressure current is required. 



The Kapp Alternator. 



The author's machine is illustrated in 

 Figs. 20 and 21. The armature-core A 

 consists of thin band-iron coiled upon 

 a cast-iron supporting-ring, and sur- 



