147 



lost by hysteresis at the lower speed was 

 approximately 25 per cent, greater than 

 at the higher speed. Taking the energy 

 absorbed per revolution in the two cases, 

 it followed that the loss per reversal was 

 approximately proportional to the square 

 of intensity of field. Some other ex- 

 periments had been made which went to 

 show that the viscous hysteresis, or the 

 viscous resistance of the iron to rapid 



Fig, 31 



Turbo Electric-Generator for 75,000 watts 

 for alternating currents. 



change of polarity, was a comparatively 

 small quantity. The intensity of field in 

 the above experiments was between 5,000 

 and 7,000. At 6,000 revolutions of the 

 apparatus the loss would be 2 HP., which 

 was about 2 per cent, of the output, mak- 

 ing a total electric efficiency of 9.") or 96 

 per cent, for the dynamo. The machine 



