﻿102 
  H. 
  A. 
  Bumstead 
  — 
  Velocities 
  of 
  Delta 
  Rays. 
  

  

  the 
  foils 
  increased 
  the 
  charge 
  received 
  by 
  the 
  Faraday 
  cylinder 
  

   by 
  2*5 
  per 
  cent 
  or 
  diminished 
  it 
  by 
  0*8 
  per 
  cent 
  according 
  to 
  

   the 
  direction 
  of 
  the 
  electric 
  field 
  ; 
  a 
  potential 
  difference 
  of 
  

   1800 
  volts, 
  they 
  find, 
  may 
  affect 
  the 
  current 
  as 
  much 
  as 
  8 
  

   per 
  cent. 
  It 
  is 
  very 
  difficult 
  to 
  believe 
  that 
  these 
  results 
  can 
  

   be 
  due 
  to 
  a 
  "drift" 
  of 
  the 
  8-electrons 
  as 
  the 
  authors 
  suppose 
  ; 
  

   in 
  their 
  magnetic 
  field, 
  the 
  radius 
  of 
  curvature 
  of 
  the 
  path 
  of 
  

   an 
  electron, 
  moving 
  with 
  a 
  velocity 
  corresponding 
  to 
  2 
  volts, 
  

  

  Fig. 
  4. 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  I 
  

  

  

  

  

  

  

  

  

  

  I- 
  

   I'- 
  

  

  TL- 
  

   TL'- 
  

  

  

  ir 
  

  

  poror 
  

  

  250 
  < 
  

  

  250 
  mum 
  

   WSSIS 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  2$' 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  Si 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  \ 
  

  

  ^*- 
  , 
  

  

  i' 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  IL' 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  26 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  -50 
  

  

  

  ^_5_ 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  00 
  

  

  

  

  JO 
  

  

  4 
  

  

  

  « 
  

  

  

  60 
  

  

  

  10 
  

  

  

  e< 
  

  

  

  * 
  

  

  

  OO 
  IK 
  

  

  O 
  IS 
  

  

  OO 
  

  

  IM» 
  

  

  NC4ATNI 
  VOLTS. 
  

  

  would 
  be 
  about 
  -0005 
  cm 
  ; 
  with 
  a 
  velocity 
  corresponding 
  to 
  1800 
  

   volts 
  about 
  , 
  02 
  cm 
  . 
  In 
  neither 
  case 
  does 
  it 
  seem 
  possible 
  that 
  

   an 
  electron 
  would 
  be 
  able 
  to 
  traverse 
  the 
  0'8 
  cna 
  between 
  the 
  

   two 
  foils. 
  In 
  fact, 
  with 
  2 
  volts, 
  it 
  appears 
  that 
  it 
  would 
  

   require 
  a 
  very 
  heavy 
  ion 
  to 
  get 
  through 
  the 
  magnetic 
  field 
  ; 
  

   with 
  1800 
  volts, 
  an 
  oxygen 
  ion 
  should 
  get 
  through. 
  

  

  §5. 
  

  

  An 
  estimate 
  of 
  the 
  reliability 
  of 
  the 
  present 
  measurements 
  

   of 
  the 
  distribution 
  in 
  velocity 
  of 
  the 
  swifter 
  S-rays 
  will 
  be 
  

   facilitated 
  by 
  a 
  consideration 
  of 
  fig. 
  4, 
  which 
  will 
  also 
  serve 
  to 
  

   give 
  a 
  clearer 
  idea 
  of 
  the 
  somewhat 
  complicated 
  phenomena 
  

   which 
  appear 
  when 
  a-rays 
  fall 
  upon 
  a 
  metal 
  in 
  a 
  high 
  vacuum. 
  

   The 
  figure 
  shows 
  graphically 
  the 
  results 
  of 
  measurements, 
  all 
  

  

  