﻿of 
  Rigidity 
  in 
  Strong 
  Fields. 
  457 
  

  

  as, 
  in 
  the 
  series 
  of 
  curves, 
  the 
  initial 
  twist, 
  6, 
  becomes 
  greater, 
  

   the 
  slope 
  of 
  the 
  curves 
  at 
  the 
  limit 
  of 
  observation 
  also 
  becomes 
  

   greater, 
  — 
  showing 
  that, 
  with 
  any 
  given 
  field, 
  the 
  possibility 
  of 
  

   reaching 
  any 
  limiting 
  value 
  for 
  the 
  increment 
  of 
  rigidity 
  

   becomes 
  more 
  and 
  more 
  remote 
  with 
  the 
  increase 
  of 
  6. 
  

  

  The 
  relation 
  between 
  the 
  rate 
  of 
  change 
  of 
  86 
  and 
  the 
  field- 
  

   strength 
  is 
  made 
  clearer 
  by 
  reference 
  to 
  fig. 
  3. 
  These 
  curves, 
  

   plotted 
  from 
  the 
  same 
  data 
  as 
  those 
  of 
  fig. 
  2, 
  show 
  86 
  to 
  be 
  an 
  

   increasing 
  function 
  of 
  6. 
  Again, 
  as 
  the 
  field 
  is 
  increased, 
  at 
  the 
  

   upper 
  limit 
  of 
  twist 
  the 
  slope 
  of 
  the 
  curves 
  increases 
  ; 
  that 
  is, 
  

   while 
  the 
  possibility 
  of 
  reaching 
  a 
  limiting 
  value 
  for 
  86 
  by 
  

   increasing 
  6 
  is 
  remote, 
  a 
  concurrent 
  increase 
  of 
  the 
  field- 
  

   strength 
  renders 
  it 
  still 
  more 
  remote. 
  

  

  Other 
  relations 
  not 
  so 
  evident 
  are 
  pointed 
  out 
  by 
  figs. 
  4 
  and 
  

   5, 
  which 
  give 
  : 
  fig. 
  4, 
  86 
  per 
  unit 
  of 
  field 
  as 
  a 
  function 
  of 
  6 
  ; 
  

   fig. 
  5, 
  86 
  per 
  unit 
  of 
  6 
  as 
  a 
  function 
  of 
  the 
  field. 
  They 
  show 
  

   that, 
  while 
  the 
  increment 
  of 
  rigidity 
  increases 
  with 
  the 
  total 
  

   strength 
  of 
  field 
  and 
  at 
  the 
  same 
  time 
  with 
  the 
  total 
  initial 
  

   torque, 
  yet, 
  per 
  unit 
  of 
  field 
  and 
  per 
  unit 
  of 
  initial 
  twist, 
  the 
  

   rate 
  of 
  increase 
  of 
  the 
  increment 
  of 
  rigidity 
  diminishes 
  and 
  

   approaches 
  the 
  limit 
  zero. 
  

  

  In 
  proportion, 
  then, 
  as 
  the 
  field 
  becomes 
  stronger, 
  the 
  incre- 
  

   ment 
  of 
  rigidity 
  varies 
  more 
  and 
  more 
  regularly 
  with 
  the 
  twist, 
  

   the 
  tendency 
  being 
  that, 
  in 
  fields 
  indefinitely 
  large 
  the 
  incre- 
  

   ment 
  of 
  rigidity 
  would 
  be 
  proportional 
  to 
  the 
  twist 
  applied. 
  

  

  In 
  conclusion, 
  in 
  preparing 
  this 
  paper, 
  acknowledgment 
  is 
  to 
  

   be 
  made 
  to 
  Dr. 
  Barns 
  of 
  the 
  University 
  for 
  assistance 
  in 
  inter- 
  

   preting 
  the 
  principles 
  involved 
  in 
  the 
  results. 
  

  

  Wilson 
  Laboratory, 
  Brown 
  University. 
  

  

  