﻿Heat 
  produced 
  by 
  Emission 
  of 
  Ions 
  from 
  Hot 
  Bodies. 
  475 
  

  

  6°K. 
  

  

  D 
  T 
  . 
  

  

  l 
  

  

  T 
  

  

  h 
  

  

  R 
  

  

  V 
  

  

  Fil. 
  sh. 
  

  

  Stan. 
  sh. 
  

  

  

  

  

  amp. 
  

  

  amp. 
  

  

  ohms. 
  

  

  volts. 
  

  

  F->S 
  

  

  S^-F 
  

  

  F->S 
  

  

  S->F 
  

  

  

  

  

  xio- 
  6 
  . 
  

  

  

  

  23-8 
  

  

  (1) 
  

  

  (2) 
  

  

  (3) 
  

  

  (4) 
  

  

  1960 
  

  

  13-54 
  

  

  1-64 
  

  

  572 
  

  

  •343 
  

  

  16-6 
  

  

  

  

  

  7-92 
  

  

  

  945 
  

  

  1-70 
  

  

  603 
  

  

  •343 
  

  

  16-26 
  

  

  23-8 
  

  

  

  4-95 
  

  

  

  

  )s 
  

  

  8-55 
  

  

  1-65 
  

  

  632 
  

  

  •342 
  

  

  16-3 
  

  

  23-8 
  

  

  4-37 
  

  

  

  

  

  1980 
  

  

  2-66 
  

  

  1-67 
  

  

  752 
  

  

  •342 
  

  

  16-51 
  

  

  23-8 
  

  

  

  

  1-14 
  

  

  

  1865 
  

  

  •84 
  

  

  1-46 
  

  

  176-9 
  

  

  •315 
  

  

  15-71 
  

  

  23-7 
  

  

  

  

  1-3] 
  

  

  

  ,, 
  

  

  2-54 
  

  

  1-46 
  

  

  161-5 
  

  

  •320 
  

  

  15-43 
  

  

  23-7 
  

  

  4-47 
  

  

  

  

  

  

  2-86 
  

  

  1-47 
  

  

  182-7 
  

  

  •320 
  

  

  15-43 
  

  

  23-7 
  

  

  

  4-42 
  

  

  

  

  s> 
  

  

  5-43 
  

  

  T50 
  

  

  207 
  

  

  •320 
  

  

  15-70 
  

  

  23-7 
  

  

  

  

  

  7-37 
  

  

  1935 
  

  

  10-51 
  

  

  1-572 
  

  

  437-1 
  

  

  •338 
  

  

  16-22 
  

  

  23-7 
  

  

  

  

  

  7-87 
  

  

  ,, 
  

  

  496 
  

  

  1-564 
  

  

  4208 
  

  

  •338 
  

  

  15-94 
  

  

  23-7 
  

  

  

  3-80 
  

  

  

  

  ,, 
  

  

  6-09 
  

  

  1-825 
  

  

  433-3 
  

  

  •338 
  

  

  15-95 
  

  

  23-7 
  

  

  3-88 
  

  

  

  

  

  " 
  

  

  217 
  

  

  1-594 
  

  

  499-5 
  

  

  •338 
  

  

  16-22 
  

  

  23-7 
  

  

  

  

  1-45 
  

  

  

  In 
  the 
  units 
  in 
  which 
  Dt 
  and 
  De 
  are 
  expressed 
  in 
  the 
  

   above 
  table 
  the 
  insensitiveness 
  of 
  the 
  galvanometer 
  was 
  

   1*24 
  X 
  10~ 
  7 
  and 
  equation 
  (13) 
  of 
  the 
  former 
  paper 
  becomes 
  

  

  BR 
  e 
  =l-24xl0- 
  7 
  [G+100E(l-01 
  + 
  -00lG)]xD 
  E 
  . 
  (13 
  1 
  ) 
  

  

  After 
  substituting 
  the 
  above 
  numbers 
  in 
  our 
  former 
  equa- 
  

   tion 
  (12) 
  the 
  resulting 
  values 
  of 
  the 
  cooling 
  effect 
  in 
  

   equivalent 
  volts 
  at 
  the 
  temperatures 
  named 
  are 
  : 
  — 
  

  

  Aver; 
  

  

  O 
  K 
  

  

  +(1 
  + 
  2) 
  

   *(3 
  + 
  4) 
  

   Means 
  .. 
  

  

  1865 
  1935 
  

  

  4-34 
  3*73 
  

  

  4-49 
  4-35 
  

  

  4-41, 
  4-04 
  

  

  Equivalent 
  

   Volts. 
  

  

  Higher 
  values 
  than 
  those 
  just 
  given 
  were 
  obtained 
  at 
  higher 
  

   temperatures 
  and 
  large 
  thermionic 
  currents, 
  but 
  the 
  measure- 
  

   ments 
  under 
  these 
  conditions 
  are 
  subject 
  to 
  large 
  errors 
  

   which 
  we 
  have 
  not 
  yet 
  succeeded 
  in 
  disentangling. 
  

  

  The 
  mean 
  of 
  the 
  above 
  values 
  of 
  </>, 
  viz. 
  4*24 
  volts, 
  com- 
  

   pares 
  with 
  4*7 
  volts 
  for 
  osmium 
  found 
  in 
  the 
  former 
  experi- 
  

   ments. 
  The 
  thermionic 
  current 
  i 
  from 
  the 
  above 
  tube 
  at 
  

   different 
  temperatures 
  6 
  has 
  been 
  measured 
  by 
  O. 
  W. 
  Richard- 
  

   son 
  and 
  K. 
  K. 
  Smith. 
  It 
  was 
  found 
  to 
  follow 
  the 
  formula 
  

   i 
  = 
  A0 
  2 
  e~ 
  1 
  ' 
  6 
  , 
  where 
  A 
  and 
  b 
  are 
  constants, 
  from 
  1500° 
  K. 
  to 
  

   2300° 
  K. 
  By 
  putting 
  b 
  = 
  (p/R 
  these 
  measurements 
  gave 
  

   </> 
  = 
  3*585 
  volts, 
  a 
  lower 
  value 
  than 
  that 
  given 
  by 
  the 
  cooling 
  

  

  