﻿Recombination 
  of 
  Ions 
  made 
  by 
  ol 
  Rays. 
  991 
  

  

  central 
  position, 
  and 
  to 
  about 
  700 
  gausses 
  in 
  the 
  others. 
  

   Observations 
  were 
  made 
  somewhat 
  differently 
  from 
  those 
  

   given 
  above, 
  the 
  motions 
  of 
  the 
  electromagnets 
  not 
  being 
  

   reversed 
  and 
  the 
  pointings 
  being 
  made 
  with 
  the 
  magnets 
  

   alternately 
  in 
  slow 
  motion 
  and 
  in 
  rapid 
  motion. 
  

  

  The 
  mean 
  values 
  of 
  the 
  deviations, 
  corresponding 
  to 
  ^D 
  

   in 
  the 
  experiments 
  described 
  above, 
  were 
  +0"01 
  mm., 
  

   — 
  0'02 
  mm., 
  and 
  —0*01 
  mm. 
  for 
  the 
  three 
  positions, 
  with 
  a 
  

   mean 
  error 
  between 
  0*01 
  mm. 
  and 
  0*02 
  mm. 
  

  

  Finally, 
  it 
  was 
  thought 
  worth 
  while 
  to 
  see 
  if 
  any 
  appreci- 
  

   able 
  change 
  in 
  the 
  trend 
  of 
  a 
  line 
  of 
  induction 
  occurred 
  

   when 
  the 
  electromagnets 
  were 
  both 
  set 
  into 
  rotation 
  in 
  the 
  

   same 
  direction 
  with 
  the 
  same 
  speed 
  as 
  before 
  — 
  slight 
  as 
  was 
  

   the 
  probability 
  of 
  obtaining 
  a 
  positive 
  result. 
  For 
  this 
  

   purpose 
  the 
  indicating 
  magnet 
  was 
  placed 
  outside 
  the 
  region 
  

   between 
  the 
  poles, 
  though 
  near 
  to 
  one 
  of 
  them, 
  and 
  in 
  such 
  

   a 
  position 
  that 
  its 
  axis 
  (and 
  the 
  lines 
  of 
  induction 
  through 
  it) 
  

   made 
  a 
  considerable 
  angle 
  (about 
  35°) 
  with 
  the 
  axis 
  of 
  the 
  

   field, 
  and 
  the 
  rod 
  supporting 
  the 
  magnet 
  was 
  placed 
  approxi- 
  

   mately 
  perpendicular 
  to 
  the 
  plane 
  containing 
  the 
  axis 
  of 
  the 
  

   field 
  and 
  the 
  lines 
  of 
  induction 
  passing 
  through 
  the 
  magnet. 
  

   Observations 
  made 
  like 
  those 
  just 
  described 
  gave 
  a 
  mean 
  

   deviation, 
  corresponding 
  to 
  J 
  D 
  in 
  the 
  earlier 
  work, 
  of 
  

   -f 
  0'03 
  mm., 
  with 
  a 
  mean 
  error 
  of 
  0*04 
  mm. 
  ; 
  indicating 
  

   therefore 
  that 
  no 
  appreciable 
  bulging 
  out 
  of 
  the 
  lines 
  was 
  

   produced 
  by 
  the 
  rotation. 
  

  

  For 
  the 
  construction 
  of 
  most 
  of 
  the 
  special 
  apparatus 
  

   used 
  in 
  the 
  experiments 
  described 
  here, 
  I 
  am 
  indebted 
  to 
  

   Mr. 
  Arthur 
  Freund, 
  mechanician 
  in 
  the 
  physical 
  laboratory. 
  

  

  The 
  Ohio 
  State 
  University, 
  

   July 
  9, 
  1913. 
  

  

  LXXXIX. 
  The 
  Recombination 
  of 
  Ions 
  made 
  by 
  a 
  Rays. 
  

   By 
  H. 
  Ogden, 
  Research 
  Scholar 
  in 
  the 
  University 
  of 
  Leeds*. 
  

  

  BrlAGGr 
  & 
  Kleeman 
  observed 
  in 
  1905 
  that 
  the 
  field 
  

   required 
  to 
  obtain 
  the 
  full 
  ionization 
  current 
  in 
  a 
  gas 
  

   in 
  which 
  a 
  given 
  number 
  of 
  ions 
  were 
  being 
  produced 
  each 
  

   second 
  was 
  always 
  very 
  much 
  greater 
  if 
  the 
  ions 
  were 
  pro- 
  

   duced 
  by 
  a 
  rays 
  than 
  if 
  they 
  were 
  produced 
  by 
  ft 
  rays. 
  They 
  

   attributed 
  this 
  difference 
  to 
  " 
  Initial 
  Recombination." 
  They 
  

   supposed 
  that 
  when 
  ions 
  were 
  formed 
  by 
  a 
  rays 
  the 
  separation 
  

   between 
  the 
  charges 
  was 
  less 
  complete 
  than 
  when 
  they 
  were 
  

   formed 
  by 
  /3 
  rays, 
  so 
  that 
  there 
  was 
  a 
  marked 
  tendency 
  for 
  

  

  * 
  Communicated 
  by 
  Prof. 
  W. 
  H. 
  Bragg, 
  F.R.S. 
  

  

  