﻿912 
  Prof. 
  0. 
  W. 
  Richardson 
  on 
  the 
  Kinetic 
  

  

  On 
  the 
  assumption 
  that 
  the 
  mean 
  sideways 
  energy 
  of 
  the 
  

   ions 
  is 
  the 
  same 
  as 
  that 
  of 
  a 
  molecule 
  of 
  gas 
  at 
  the 
  tem- 
  

   perature 
  6 
  o£ 
  the 
  metal, 
  the 
  value 
  of 
  ^nmu 
  2 
  may 
  be 
  

   calculated 
  by 
  the 
  kinetic 
  theory 
  of 
  oases. 
  It 
  is 
  in 
  fact 
  

  

  equal 
  to 
  i/> 
  -f*, 
  where 
  p 
  is 
  the 
  value 
  of 
  the 
  standard 
  

  

  atmosphere 
  in 
  dynes 
  per 
  cm. 
  2 
  Putting 
  ;> 
  = 
  1'01 
  x 
  10 
  G 
  and 
  

   0=1500° 
  abs.. 
  we 
  find 
  

  

  ±nmu 
  2 
  =2'8 
  x 
  10 
  G 
  . 
  

  

  This 
  agrees 
  very 
  well 
  with 
  the 
  experimental 
  value. 
  

  

  The 
  smooth 
  curves 
  drawn 
  in 
  fig. 
  7 
  are 
  of 
  the 
  form 
  

  

  required 
  if 
  Maxwell's 
  law 
  of 
  distribution 
  holds. 
  The 
  one 
  

   on 
  the 
  right 
  is 
  

  

  / 
  /=l-lll./--r- 
  ,, 
  ^.r-. 
  

  

  and 
  that 
  00 
  the 
  left 
  19 
  

  

  y=l-07&A 
  " 
  1;,: 
  '.''- 
  

  

  (where 
  Lf=*0318 
  cm.). 
  It 
  is 
  easy 
  to 
  deduce 
  the 
  proper 
  

   values 
  o£ 
  the 
  constants 
  for 
  these 
  curve-, 
  since 
  they 
  are 
  both 
  

   determined 
  by 
  the 
  coordinates 
  of 
  the 
  maximum 
  point, 
  and 
  

   tin- 
  can 
  usually 
  be 
  judged 
  fairly 
  accurately 
  from 
  the 
  look 
  

   of 
  the 
  observations. 
  For 
  the 
  maximum 
  point 
  we 
  have 
  

  

  <I 
  ; 
  / 
  =\(2,r 
  ( 
  '- 
  / 
  '"-2h,-e-^) 
  = 
  0; 
  

   da 
  

  

  SO 
  that 
  

  

  *«V<£ 
  (i«) 
  

  

  Also 
  

  

  so 
  that 
  

  

  eVm 
  

  

  A=~p=eb 
  !/m 
  , 
  .... 
  (19) 
  

  

  whore 
  Xmy 
  m 
  are 
  the 
  coordinates 
  of 
  the 
  maximum 
  point. 
  

   By 
  applying 
  equation 
  (7) 
  we 
  see 
  that 
  

  

  Vne 
  

  

  9 
  A 
  9 
  — 
  

  

  y=u 
  

  

  ia?=Aa?e-4MM 
  x2 
  

  

  so 
  that 
  . 
  Yne 
  

  

  Changing 
  the 
  units 
  to 
  centimetres 
  we 
  find 
  from 
  the 
  above 
  

  

  V 
  • 
  716 
  

  

  numbers 
  TiT/p 
  = 
  49, 
  which 
  gives 
  U6 
  = 
  7*7 
  X 
  10 
  G 
  and 
  

  

  K 
  = 
  5*2xl0 
  3 
  . 
  This 
  value 
  is 
  somewhat 
  higher 
  than 
  those 
  

   obtained 
  previously. 
  

  

  