﻿of 
  the 
  Mechanical 
  Equivalent 
  of 
  Heat. 
  

  

  29 
  

  

  Fisr. 
  2. 
  

  

  53S-0 
  

  

  538' 
  

  

  99-S 
  C 
  

  

  IGO 
  w 
  C 
  

   T"e 
  mpera 
  t 
  ure 
  

  

  100-5 
  C 
  

  

  The 
  theoretical 
  curve 
  is 
  obtained 
  from 
  Clapeyrons 
  relation 
  

  

  l=(v-»)t||, 
  

  

  to 
  show 
  the 
  change 
  of 
  latent 
  heat 
  with 
  temperature. 
  (Since 
  the 
  values 
  of 
  

   V 
  and 
  — 
  are 
  not 
  known 
  with 
  the 
  same 
  accuracy 
  as 
  L 
  ? 
  the 
  slope 
  of 
  the 
  

  

  dr 
  

  

  curve 
  only 
  has 
  been 
  taken 
  from 
  this 
  relation. 
  This 
  is 
  sufficient 
  for 
  the 
  

   purpose 
  of 
  reducing 
  the 
  results.) 
  

  

  It 
  will 
  be 
  noticed 
  that 
  the 
  more 
  accurate 
  methods 
  of 
  measurement 
  

   give 
  values 
  which 
  show 
  clearly 
  the 
  agreement 
  with 
  the 
  thermo- 
  

   dynamical 
  result. 
  

  

  On 
  comparing 
  this 
  with 
  the 
  author's 
  results, 
  which 
  are 
  

   measured 
  directly 
  in 
  mean 
  calories, 
  it 
  follows 
  that 
  

  

  " 
  538-5 
  x 
  4-188 
  = 
  538-88 
  J, 
  

   l 
  - 
  e 
  -> 
  J 
  = 
  4*185 
  + 
  0*002 
  joules 
  per 
  mean 
  calorie. 
  

  

  It 
  will 
  be 
  noticed 
  that 
  this 
  is 
  in 
  exact 
  agreement 
  with 
  the 
  

   values 
  obtained 
  by 
  the 
  earlier 
  experimenters 
  — 
  Schuster 
  and 
  

   Gannon, 
  Reynolds 
  and 
  Moorby, 
  Callendar 
  and 
  Barnes, 
  — 
  and 
  

   with 
  the 
  values 
  deduced 
  on 
  separate 
  occasions 
  (from 
  all 
  data 
  

   then 
  available) 
  by 
  Griffiths 
  and 
  by 
  Barnes 
  ; 
  on 
  the 
  other 
  

   hand, 
  this 
  value 
  and 
  those 
  obtained 
  by 
  the 
  more 
  recent 
  experi- 
  

   menters 
  are 
  certainly 
  too 
  discordant 
  to 
  be 
  reconciled. 
  

  

  This 
  agreement 
  between 
  the 
  values 
  given 
  by 
  the 
  classical 
  

   experiments 
  and 
  the 
  value 
  given 
  by 
  a 
  method 
  so 
  different 
  as 
  

   the 
  present 
  substantially 
  increases 
  the 
  probability 
  that 
  the 
  

   value 
  of 
  the 
  Mechanical 
  Equivalent 
  lies 
  between 
  4*184 
  and 
  

   4*185 
  joules 
  per 
  mean 
  calorie. 
  

  

  