66 



Induction. 

 2.000 

 3,000 

 4.000 

 5,000 

 6,000 

 7,000 

 8.000 

 9,000 

 10,000 



A third column has been added, show- 

 ing the HP. transformed into heat, and 

 therefore wasted per ton of armature- 

 core, if the frequency is 100 complete 

 periods per second. 



In the paper referred to above, Pro- 

 fessor Ewing says that mechanical vibra- 

 tions tend to decrease the amount of 

 energy dissipated per cycle ; and that, as 

 the armatures of dynamo machines are, 

 whilst working, in a continual state of 

 vibration, it will be very much less than 

 indicated by the figures he found when 

 experimenting on pieces of iron which 

 were at rest. The author, however, 

 doubts whether this view can safely be 

 accepted. The vibrations of an armature 



