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BELL SYSTEM TECHNICAL JOURNAL 



per cent. Fij^. 14 shows an initial magnetization curve wliich gives a 

 value of the initial permeability agreeing accurately with the value 

 determined ballistically. 



A Huxmeter with no restoring torque is also useful in certain t>'pes of 

 current measurements. If the average value of a current which 

 fluctuates too nuich to he read on a slowly moving meter is desired, it 



6000 



5000 



4 000 



B 3000 



2000 



1000 



0.5 



Fig. 14 — All initial magnetization curve of tlie specimen of 78.1 per cent 

 nickel permalloy. 



can be integrated on the fluxmeter, and the average value obtained by 

 dividing the total quantity of electricity which has passed through by 

 the time during which the measurement was made. Also if a current is 

 too small to be read directly on a galvanometer it may be possible to 

 maintain it for a sufficient length of time to give a readable deflection 

 on the fluxmeter, and again the current will be obtained by dividing 

 by the time. 



In conclusion I wish to thank Dr. R. M. Bozorth for suggestions 

 given during the development of the apparatus, and Mr. A. W. Metz 

 for his assistance in taking the curves. 



