﻿2S 
  

  

  Mr. 
  E. 
  Tabor 
  Lattey 
  on 
  the 
  

  

  was 
  engraved 
  ; 
  a 
  beam 
  of 
  b'ght 
  from 
  a 
  Nernst 
  lamp 
  passed 
  

   through 
  this 
  and 
  thence 
  obliquely 
  across 
  the 
  chamber. 
  The 
  

   upper 
  boundary 
  o£ 
  the 
  fog 
  could 
  then 
  be 
  distinguished 
  

   through 
  a 
  telescope 
  by 
  means 
  of 
  the 
  light 
  scattered 
  by 
  the 
  

   fog 
  particles. 
  

  

  CSS 
  

  

  s: 
  

  

  \\\'N\'S\ 
  

  

  \\\ 
  \\ 
  \S 
  

  

  -c- 
  

  

  :sx 
  

  

  SX3 
  

  

  a 
  

  

  The 
  sLaded 
  portions 
  are 
  of 
  "brass, 
  the 
  vertical 
  walls 
  of 
  glass. 
  Water 
  

   is 
  represented 
  by 
  broken 
  horizontal 
  lines. 
  

  

  In 
  some 
  of 
  the 
  earlier 
  experiments 
  a 
  simpler 
  apparatus 
  

   without 
  a 
  water-jacket 
  was 
  used 
  and 
  difficulties, 
  due 
  to 
  heat 
  

   convection 
  currents, 
  were 
  often 
  experienced; 
  these 
  results 
  

   are 
  given 
  in 
  the 
  table 
  on 
  page 
  29 
  under 
  the 
  heading 
  " 
  first 
  

   set" 
  ; 
  not 
  only 
  was 
  the 
  observation 
  chamber 
  different 
  in 
  

   these, 
  but 
  the 
  electrolytic 
  apparatus 
  was 
  also 
  different, 
  and 
  

   hence 
  the 
  rate 
  of 
  fall 
  of 
  the 
  fog 
  under 
  the 
  influence 
  of 
  gravity 
  

   was 
  different 
  from 
  that 
  obtained 
  in 
  the 
  ^^ 
  second 
  set 
  ^' 
  with 
  

   the 
  modified 
  apparatus. 
  

  

  By 
  this 
  method 
  the 
  charge 
  on 
  a 
  particle 
  is 
  deduced 
  from 
  

   the 
  change 
  of 
  velocity 
  produced 
  by 
  a 
  known 
  field. 
  Since 
  

   the 
  charges 
  on 
  the 
  particles 
  vary 
  in 
  sign, 
  the 
  effect 
  of 
  a 
  field 
  

   is 
  to 
  accelerate 
  some 
  and 
  to 
  retard 
  others 
  in 
  their 
  fall 
  ; 
  this 
  

   made 
  the 
  outline 
  of 
  the 
  fog 
  somewhat 
  indistinct, 
  but 
  it 
  was 
  

   found 
  that 
  the 
  boundary 
  of 
  the 
  rapidly 
  falling 
  portion 
  could 
  

  

  