﻿THE 
  

   LONDON, 
  EDINBURGH, 
  and 
  DUBLIN' 
  

  

  PHILOSOPHICAL 
  MAGAZINE 
  

  

  AND 
  

  

  JOURNAL 
  OF 
  SCIENCE. 
  

  

  ♦ 
  

  

  [FIFTH 
  SERIES.] 
  

  

  MARCH 
  1898. 
  

  

  XXIV. 
  Notes 
  on 
  Thermometry. 
  By 
  C. 
  Chree, 
  Sc 
  Z>., 
  F.R.S* 
  

  

  § 
  1. 
  Introductory. 
  

  

  2. 
  Natural 
  scale 
  of 
  ideal 
  thermometer. 
  

   3-7. 
  Properties 
  of 
  real 
  glass, 
  fixed 
  and 
  movable 
  zero 
  scales. 
  

   8-10. 
  Depression 
  of 
  zero. 
  

   11-13. 
  Experimental 
  relation 
  of 
  different 
  scales, 
  moderate 
  temperatures. 
  

   14-16. 
  „ 
  „ 
  „ 
  at 
  temp, 
  over 
  100° 
  0. 
  

  

  17-19. 
  „ 
  „ 
  „ 
  at 
  low 
  temperatures. 
  

  

  Occurrence 
  of 
  Constant 
  Coefficients. 
  

  

  Ay 
  A 
  2 
  , 
  &c. 
  in 
  law 
  of 
  thermal 
  expansion 
  of 
  mercury. 
  

  

  a 
  v 
  a 
  2 
  , 
  &c, 
  „ 
  „ 
  „ 
  glass 
  (fixed 
  zero). 
  

  

  b 
  v 
  b 
  2 
  , 
  &c, 
  „ 
  „ 
  „ 
  „ 
  (movable 
  zero). 
  

  

  &,', 
  b. 
  2 
  ', 
  &c, 
  „ 
  after-effect 
  in 
  glass. 
  

  

  d 
  1} 
  (U, 
  &c., 
  „ 
  depression 
  of 
  thermometers' 
  zero 
  with 
  temperature. 
  

  

  e,=A, 
  —a 
  lf 
  &c. 
  

  

  e=mean 
  coefficient 
  of 
  expansion 
  of 
  mercury 
  in 
  glass 
  between 
  0° 
  and 
  100° 
  C. 
  

  

  Introductory, 
  

  

  § 
  1. 
  /^\F 
  late 
  years 
  much 
  has 
  been 
  done, 
  especially 
  in 
  

   \J 
  France 
  and 
  Germany, 
  to 
  increase 
  the 
  accuracy 
  of 
  

   the 
  measurement 
  of 
  temperatures 
  by 
  means 
  of 
  mercury 
  

   thermometers. 
  An 
  excellent 
  account, 
  with 
  illustrations, 
  of 
  

   some 
  of 
  the 
  more 
  important 
  practical 
  results 
  is 
  given 
  in 
  

   Chap. 
  II. 
  of 
  Waldo's 
  ' 
  Modern 
  Meteorology 
  ' 
  ; 
  but 
  the 
  scope 
  

   of 
  this 
  work 
  hardly 
  allows 
  of 
  the 
  subject 
  being 
  treated 
  in 
  

   detail 
  except 
  where 
  meteorological 
  questions 
  are 
  directly 
  

   concerned. 
  With 
  this 
  partial 
  exception, 
  I 
  know 
  of 
  no 
  

  

  * 
  Communicated 
  by 
  the 
  Kew 
  Observatory 
  Committee. 
  

   Phil. 
  Mag. 
  S. 
  5. 
  Vol. 
  45. 
  No. 
  274. 
  Mar. 
  1898, 
  Q 
  

  

  