258 



Major K. L. Hippisley 

 Table J. 



4. When the impressed E.M.F. is sinusoidal, we substitute for 

 dB/dt in the equation 



E sinjp*- = Hi (14), 



having determined the various values of dB /eft, as in the foregoing. 

 As by the present method the value of m changes abruptly from 



