466 



Scientific Proceedinr/x, Royal Dublin Society. 



We thus see that even with the enormous magnetizing force of 

 1300 units saturation is not readied with this specimen. The 

 actual magnetic moment per gramme produced by this field is 

 0-0701 c. g. s. units. 



In the accompanying diagram, Fig. 1, the foregoing table is 

 plotted in a curve, the abscissse being magnetizing force, and the 



50 100 150 200 250 300 350 400 450 500 



Magnetising Force in C. G. S. Units. 

 Pig. 1. 



ordinates one hundred times the corresponding magnetic moment. 

 This exaggeration of the moment is necessary in order to show 

 on the same diagram the curve resulting from similar experiments 

 with ordinary steel and glass-hard steel. 



A series of comparative experiments were now made with the 

 different ingots, though the field employed, 260 c. g. s. units, was 

 probably not large enough to raise them to saturation ; a larger 

 current was impracticable, being found to heat the helix unduly. 

 The current was flushed on and off for 30 seconds in each 

 case. 



