838 Miss M. B. Moir on Magnetic Properties of a 



value of the intensity was found to be lower than previously > 

 and the effect of quenching even more marked than before. 

 The crossing of the curves at the two temperatures in the 

 annealed state occurs at a field value of 102 c.G.s. units, and 

 the magnetic quality at 15° C, after immersion in liquid air, 

 is lower than before immersion for fields less than 170 C.G.s. 

 units. An examination of this specimen when quenched pro- 

 duced exactly the same results as in the previous cases — that 

 is to say, the magnetic quality when the temperature is 

 lowered to —190° C. is less than at room-temperature for the 

 whole range examined, and returns to its original value when 

 the temperature is allowed to rise again. 



Specimens IV., V., and VI. (12 per cent. Cr., 16 per cent. 

 Cr., and 20 per cent. Cr.). — The next three specimens showed 

 on examination no marked peculiarities, so I shall not discuss 

 them separately. The results obtained on testing them are 

 exhibited in Tables IV., V., and VI., and the corresponding 



Table IV. (Fig. 5.) 

 12 per cent. Cr. 



Thermal treatment 



Annealed at 900° C. 



Quenched at 900° C. 







Temperature of test 



15° C. 



-190° C. 



15° C. 



- 190° C. 





H. 



I. 



I. 



I. 



I. 

 13 



10 



80 



70 



20 



20 



440 



380 



45 



36 



40 



765 



750 



112 



100 



60 



850 



840 



235 



210 



100 



936 



932 



485 



470 



150 



1008 



1018 



653 



638 



Table V. (Fig. 6.) 

 16 per cent. Cr. 



Thermal treatment 



Annealed at 900° C. 



Quenched 



at 900° C. 







Temperature of test 



15° C. 



-190° C. 



15° O. 



- 190° C. 





H. 



I. 



I. 



I. 



I. 



10 



70 



55 



17 



12 



20 



320 



235 



41 



35 



40 



635 



608 



84 



76 



60 



710 



695 



162 



145 



100 



780 



784 



360 



340 



150 



850 



865 



508 



492 



