﻿on 
  the 
  Hysteresis 
  Loss 
  in 
  Iron 
  in 
  a 
  Rotating 
  Field. 
  871 
  

  

  effect 
  o£ 
  the 
  magnetizing-coils. 
  The 
  results 
  in 
  fig. 
  4 
  were 
  

   obtained 
  after 
  the 
  iron 
  had 
  been 
  heated 
  to 
  580° 
  and 
  cooled 
  

   slowly. 
  These 
  experiments 
  show 
  that 
  the 
  effect 
  of 
  increasing 
  

   the 
  temperature 
  of 
  iron 
  is 
  to 
  greatly 
  reduce 
  the 
  hysteresis 
  

  

  Fig. 
  4. 
  

  

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  J, 
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  DUCT/ 
  ON 
  CCS 
  UN 
  J 
  TS 
  

  

  loss 
  at 
  a 
  given 
  induction, 
  and 
  to 
  cause 
  the 
  maximum 
  to 
  

   occur 
  at 
  a 
  lower 
  value 
  of 
  B. 
  At 
  a 
  temperature 
  of 
  580° 
  C. 
  

   the 
  maximum 
  hysteresis 
  loss 
  occurs 
  at 
  an 
  induction 
  density 
  

   of 
  11,000 
  C.G.S. 
  units 
  instead 
  of 
  16,000, 
  while 
  the 
  maximum 
  

   hysteresis 
  loss 
  is 
  only 
  2600 
  as 
  compared 
  with 
  a 
  maximum 
  of 
  

   over 
  15,000 
  per 
  c.c. 
  per 
  cycle 
  at 
  ordinary 
  temperatures. 
  The 
  

   effect 
  of 
  heating 
  to 
  580°, 
  as 
  shown 
  in 
  fig. 
  4, 
  is 
  most 
  marked 
  ; 
  

   although 
  the 
  actual 
  maximum 
  hysteresis 
  loss 
  is 
  not 
  greatly 
  

   filtered 
  at 
  the 
  higher 
  temperature, 
  the 
  reduction 
  in 
  the 
  hyste- 
  

   resis 
  loss 
  at 
  the 
  lower 
  temperature 
  is 
  considerable. 
  The 
  

   shape 
  of 
  the 
  curve 
  between 
  ergs 
  per 
  cycle 
  and 
  B 
  is 
  quite 
  

   different, 
  the 
  hysteresis 
  loss 
  falling 
  off 
  much 
  more 
  rapidly 
  

   from 
  the 
  maximum. 
  

  

  The 
  permeability 
  of 
  the 
  iron 
  is 
  not 
  greatly 
  affected 
  by 
  

   changes 
  in 
  temperature 
  within 
  the 
  limits 
  of 
  the 
  experiment, 
  

   a< 
  was 
  shown 
  by 
  Morris 
  *. 
  

  

  The 
  above 
  experiments 
  were 
  carried 
  out 
  at 
  the 
  Applied 
  

   Electricity 
  Laboratories 
  of 
  the 
  University 
  of 
  Liverpool, 
  and 
  

   the 
  authors 
  thank 
  Professor 
  Marchant 
  for 
  his 
  valuable 
  advice 
  

   and 
  assistance. 
  

  

  * 
  Phil. 
  Mag. 
  Sept. 
  1897. 
  

   3N2 
  

  

  