﻿High 
  Temper 
  atiu'es. 
  

  

  189 
  

  

  Table 
  YIII. 
  

   Variations 
  of 
  temperature 
  within 
  electric 
  oven. 
  

  

  Distance 
  of 
  

  

  thermo-electric 
  

  

  junction 
  from 
  

  

  middle-point 
  

  

  of 
  oven. 
  

  

  Fall 
  in 
  temperature 
  as 
  compared 
  with 
  center 
  of 
  oven. 
  

  

  Coil 
  wound 
  uniformly. 
  

  

  At 
  640°: 
  At 
  840° 
  At 
  1040' 
  

  

  4-0«™ 
  to 
  the 
  right 
  — 
  3-4' 
  

   7-5 
  " 
  " 
  -U-T 
  

   4-0 
  " 
  left 
  ' 
  — 
  3-2 
  

   7-5 
  " 
  " 
  : 
  -14.-4 
  

  

  100 
  " 
  '^ 
  I 
  

  

  - 
  3-4° 
  

   -11-7 
  

  

  — 
  2-7 
  

   -11-1 
  

  

  -2-7^ 
  

   -8-7 
  

   -1-9 
  

   ■9-9 
  

  

  Coil 
  wound 
  logarithmically. 
  

  

  At 
  620° 
  At 
  820° 
  At 
  1010° 
  At 
  1150 
  

  

  -M-3' 
  

   + 
  3-5 
  

   -f-1-3 
  

   -M-9 
  

   -1-0 
  1 
  

  

  -f-0-6' 
  

  

  4-2-1 
  

   + 
  1-2 
  

   -t-1-8 
  

   + 
  0-7 
  

  

  -0-3° 
  

   -0-3 
  

  

  + 
  1-4 
  

  

  -I- 
  2-7 
  

   + 
  2-4 
  

  

  -0-7 
  = 
  

   -1-8 
  

   -f 
  2-0 
  

  

  -fr7 
  

  

  -fO-8 
  

  

  Table 
  IX 
  contains 
  the 
  results 
  obtained 
  with 
  the 
  platin-iridium 
  

   bulb 
  in 
  the 
  new 
  form 
  of 
  coil, 
  excepting 
  the 
  first 
  two 
  sets, 
  which 
  

   were 
  made 
  with 
  the 
  uniform 
  winding 
  and 
  partitions 
  in 
  the 
  tube 
  

   close 
  to 
  the 
  end 
  of 
  the 
  bulb. 
  For 
  these 
  two 
  cases 
  an 
  integral 
  

   value 
  of 
  the 
  distribution 
  of 
  temperature 
  along 
  the 
  bulb 
  as 
  

   measured 
  at 
  the 
  time 
  has 
  been 
  added 
  as 
  a 
  correction. 
  We 
  lay 
  

   no 
  especial 
  stress 
  upon 
  the 
  agreement 
  of 
  these 
  values 
  with 
  the 
  

   following 
  ones 
  and 
  give 
  the 
  results 
  only 
  because 
  they 
  happen 
  

   to 
  have 
  been 
  made 
  with 
  the 
  same 
  gas 
  filling. 
  Observations 
  

   during 
  which 
  the 
  oven 
  current 
  was 
  reversed 
  are 
  indicated 
  in 
  

   the 
  table 
  by 
  an 
  asterisk 
  (■^). 
  

  

  The 
  values 
  for 
  the 
  electromotive 
  force 
  e,_ 
  refer 
  to 
  the 
  element 
  

   T„ 
  which 
  throughout 
  the 
  observations 
  lay 
  at 
  the 
  middle 
  point 
  

   of 
  the 
  bulb. 
  The 
  results 
  obtained 
  with 
  the 
  logarithmically 
  

   wound 
  spiral 
  contain 
  no 
  correction 
  for 
  variations 
  in 
  temperature 
  

   along 
  the 
  bulb, 
  although, 
  as 
  may 
  be 
  seen 
  from 
  Table 
  YIII, 
  the 
  

   ends 
  of 
  the 
  bulb 
  for 
  the 
  lower 
  temperatures 
  are 
  somewhat 
  over- 
  

   heated. 
  The 
  values 
  in 
  the 
  last 
  column 
  (Table 
  IX) 
  give 
  the 
  

   differences 
  between 
  the 
  observed 
  temperatures 
  obtained 
  from 
  

   the 
  gas 
  thermometer 
  and 
  those 
  taken 
  from 
  a 
  mean 
  curve 
  drawn 
  

   through 
  the 
  plotted 
  readings 
  of 
  the 
  thermo-element 
  T^. 
  The 
  

   mean 
  value 
  of 
  the 
  error 
  thus 
  obtained 
  amounts 
  to 
  rb 
  0'8o. 
  

  

  Table 
  IX. 
  

  

  

  

  Bulb 
  (Xo. 
  TI).— 
  Platinum 
  with 
  20 
  

  

  per 
  cent 
  iridium 
  

  

  Gas—] 
  

  

  S'ltrogen. 
  

  

  Y^=208-222ccni. 
  y^=( 
  

  

  )-87o. 
  3,3r=0-000025. 
  

  

  

  After 
  filling. 
  Ho 
  a 
  

  

  t 
  

  

  Co. 
  

  

  Obs.-Ca 
  

  

  1st 
  day 
  286-44 
  0-003662 
  

  

  

  

  

  4th 
  " 
  

  

  625-9° 
  

  

  5399 
  

  

  0-0° 
  

  

  

  626-7 
  

  

  5J,0J, 
  

  

  -hO'S 
  

  

  

  nO'S 
  

  

  627-2 
  

  

  + 
  0-6 
  

  

  

  815-9 
  

  

  7Jf08 
  

  

  + 
  0-8 
  

  

  

  908-4 
  

  

  8J^39 
  

  

  + 
  1-1 
  

  

  

  1003-5 
  

  

  9530 
  

  

  + 
  1-7 
  

  

  

  1121-6 
  

  

  10910 
  

  

  + 
  4'o 
  

  

  

  1128-3 
  

  

  11000 
  

  

  -\-3-8 
  

  

  