The Magnetic Properties of almost pure Iron. 373 



Table III. 









1 



2 



3 



4 



5 



6 



^ i 



10 



Change of B, 10 



cells 





















| 



exciting through 



extra 

















i 







13600 



4030 



1990 



927 



576 



285 



175 



42 I 



Change of B, 56 



cells 



















exciting through 



extra 

















j 







13800 



3690 



1680 



944 



529 



256 





40 | 



\ 



zero to a value equal to the then coercive force, the specimen was 

 tapped four times with a piece of wood, and at each stroke it 

 delivered 105, 40, 56, 30 C.G.S. units per square centimetre in the 

 direction of acquirement of magnetism. 



(6) Maximum B = 3770, maximum H = 1*003. The force was 

 varied from one maximum through zero to 0*620 and a* deflection 

 corresponding to B = 3620 observed. The figures in Table IV give 

 the results obtained by closing the secondary circuit at known 

 intervals of time "after reversal. 



Table IV. 



! 







1 



2 



3 



, 1 



i 



Change of B, 5 cells exciting through extra 



3620 



536 



95 



25 



10 | 



One would expect the maximum induction to be affected in this 

 case, since it is on the steep part of the curve : the figures obtained 

 are given in Table V. 



Table V. 





1 



2 



3 



5 ] 





Change of B, 5 cells exciting through extra 



! 



3770 796 



23 



14 



6-5 ! 



1 



The curve in fig. 1 shows this effect clearly; the points 1, 2, 3, 

 for any force show the observed change of induction density B when 

 the secondary key is raised J second, 1 second after reversal, and 



