﻿Dr. 
  C. 
  Chree's 
  Notes 
  on 
  Thermometry. 
  

   Table 
  III. 
  

  

  217 
  

  

  

  Verre 
  clur. 
  

  

  16in. 
  

  

  59m. 
  

  

  Si0 
  2 
  

  

  71-5 
  

   110 
  

   145 
  

  

  1-5 
  

  

  64 
  

  

  0-7 
  

   99-6 
  

  

  67-3 
  

  

  14-0 
  

  

  7-0 
  

  

  20 
  

  

  2 
  V 
  5 
  

  

  70 
  

  

  6 
  V 
  2 
  

  

  7195 
  

   110 
  

  

  12-0 
  

   50 
  

  

  0-05 
  

   100-00 
  

  

  Na,0 
  

  

  CaO 
  

  

  B,0 
  3 
  

  

  A1 
  2 
  3 
  

  

  Al 
  3 
  + 
  Fe 
  3 
  ... 
  

  

  ZnO 
  

  

  K.,0 
  

  

  S0 
  3 
  

  

  MoO, 
  

  

  

  100-00 
  

  

  The 
  data 
  for 
  16 
  111 
  and 
  59 
  m 
  refer 
  apparently 
  to 
  the 
  ingre- 
  

   dients 
  as 
  put 
  into 
  the 
  melting-pot. 
  Actual 
  analysis 
  of 
  16 
  m 
  

   by 
  Tornoe 
  gave 
  about 
  1 
  per 
  cent, 
  of 
  S0 
  3 
  . 
  The 
  data 
  for 
  

   verre 
  dur 
  are 
  from 
  an 
  analysis 
  by 
  Tornoe. 
  Similar 
  data 
  will 
  

   be 
  found 
  in 
  Guillaume's 
  ' 
  Thermometries 
  p. 
  144 
  and 
  p. 
  160. 
  

   The 
  first-mentioned 
  page 
  gives 
  details 
  as 
  to 
  the 
  degree 
  of 
  

   variability 
  of 
  composition 
  in 
  different 
  samples 
  of 
  verre 
  dur. 
  

  

  The 
  relations 
  to 
  one 
  another 
  of 
  the 
  natural 
  scales 
  of 
  verre 
  

   dur 
  (movable 
  zero), 
  hydrogen, 
  and 
  nitrogen 
  thermometers 
  

   have 
  been 
  examined 
  experimentally 
  at 
  the 
  Bureau 
  Inter- 
  

   national. 
  From 
  the 
  observations 
  formulae 
  of 
  the 
  type 
  (7) 
  

   have 
  then 
  been 
  calculated. 
  For 
  instance, 
  the 
  formula* 
  found 
  

   to 
  connect 
  f, 
  temperature 
  on 
  the 
  hydrogen 
  scale, 
  and 
  t 
  r 
  y 
  tem- 
  

   perature 
  on 
  the 
  verre 
  dur 
  scale, 
  throughout 
  the 
  range 
  0° 
  to 
  

   100° 
  O. 
  is 
  

  

  t'-t=t{lW-i) 
  x 
  10- 
  6 
  (62-296 
  -0*48946* 
  + 
  -0012805* 
  2 
  ). 
  

  

  These 
  formulae— 
  which 
  accord 
  very 
  closely 
  with 
  the 
  actual 
  

   observations 
  — 
  are 
  finally 
  employed 
  to 
  calculate 
  tables 
  f 
  of 
  

   differences 
  between 
  the 
  several 
  scales. 
  

  

  At 
  the 
  ReichsanstaltJ 
  the 
  scales 
  of 
  16 
  m 
  , 
  59 
  m 
  , 
  and 
  other 
  

   Jena 
  glasses 
  have 
  been 
  compared 
  w 
  r 
  ith 
  that 
  of 
  verre 
  dur, 
  and 
  

   formulae 
  of 
  the 
  Callendar 
  type 
  have 
  then 
  been 
  calculated 
  to 
  

   suit 
  the 
  observed 
  differences 
  ; 
  such, 
  for 
  instance, 
  as 
  

  

  * 
  16 
  _£ 
  = 
  o 
  -0259{(£/100)-(£/100) 
  2 
  }; 
  

  

  * 
  Guillaume's 
  Thermometrie, 
  p. 
  284. 
  

  

  t 
  Ibid. 
  pp. 
  328-332 
  ; 
  also 
  Bureau 
  International's 
  Travaux 
  et 
  Memoires, 
  

   vol. 
  x. 
  1894 
  (Thermometres 
  JStalons, 
  par 
  Ch. 
  Ed. 
  Guillaume, 
  pp. 
  32, 
  33). 
  

   % 
  Wiss. 
  Abhandl. 
  vol. 
  ii. 
  pp. 
  39, 
  40. 
  

  

  