﻿Energy 
  of 
  Negative 
  Electrons 
  emitted 
  by 
  Hot 
  Bodies. 
  361 
  

  

  o£ 
  the 
  platinum 
  strip 
  which 
  emitted 
  the 
  ions 
  was 
  between 
  

   •04 
  and 
  '006 
  ohm. 
  That 
  of 
  the 
  leads 
  about 
  # 
  1 
  ohm. 
  The 
  

   heating 
  current 
  was 
  usually 
  in 
  the 
  neighbourhood 
  of 
  2 
  

   amperes. 
  The 
  lower 
  plate 
  L 
  was 
  supported 
  by 
  a 
  brass 
  ring- 
  

   soldered 
  to 
  the 
  brass 
  plate 
  B. 
  The 
  upper 
  plate 
  and 
  guard- 
  

   ring 
  were 
  rigidly 
  connected 
  together 
  and 
  insulated 
  from 
  each 
  

   other 
  by 
  ebonite 
  pieces. 
  These 
  are 
  not 
  shown 
  in 
  fig. 
  2. 
  

  

  Fig. 
  2. 
  

  

  PUMP. 
  &.c. 
  

  

  

  w 
  Centimlters 
  

  

  Additional 
  ebonite 
  supports, 
  also 
  not 
  shown, 
  enabled 
  it 
  to 
  

   rest 
  on 
  the 
  lower 
  plate, 
  and 
  also 
  kept 
  it 
  insulated 
  from 
  the 
  

   latter. 
  These 
  supports 
  also 
  ensured 
  that 
  the 
  plates 
  were 
  

   always 
  at 
  a 
  constant 
  distance 
  apart 
  and 
  parallel 
  to 
  each 
  other. 
  

   Connexion 
  with 
  the 
  electrometer 
  was 
  made 
  by 
  means 
  of 
  a 
  

   stout 
  wire 
  soldered 
  to 
  the 
  top 
  of 
  the 
  upper 
  plate, 
  which 
  

   supported 
  a 
  mercury-cup 
  M 
  insulated 
  from 
  the 
  shield 
  S 
  by 
  

   ebonite. 
  The 
  wire 
  connecting 
  it 
  to 
  the 
  electrometer 
  system 
  

   dipped 
  into 
  this 
  mercury-cup. 
  

  

  