﻿234 
  Mr. 
  S. 
  H. 
  Burbury 
  on 
  Irreversible 
  

  

  which, 
  owing 
  to 
  the 
  minus 
  sign 
  prefixed, 
  is 
  necessarily 
  positive 
  

  

  v 
  2 
  U 
  

  

  if 
  not 
  zero, 
  and 
  then 
  only 
  zero 
  when 
  K= 
  ~j~ 
  ^ 
  0r 
  every 
  wave 
  

  

  and 
  resonator. 
  , 
  ; 
  . 
  

  

  A 
  Polarized 
  Wave. 
  

  

  16. 
  We 
  cannot 
  in 
  calculating 
  entropy, 
  as 
  we 
  did 
  in 
  calcu- 
  

   lating 
  energy, 
  use 
  K^ 
  and 
  K 
  2 
  instead 
  of 
  the 
  principal 
  intensities 
  

   K, 
  K'. 
  For 
  Kj 
  and 
  K 
  2 
  lie 
  between 
  K 
  and 
  K'. 
  

  

  Therefore 
  by 
  art. 
  1 
  

  

  av\ 
  °& 
  bv' 
  3 
  ~~ 
  J 
  av\ 
  °^ 
  bv 
  z 
  ~~ 
  ) 
  

   is 
  greater 
  than 
  

  

  Let 
  us 
  then 
  define 
  

  

  •--^(-S-O-^NS^) 
  

  

  to 
  be 
  the 
  actual 
  entropy 
  of 
  the 
  wave 
  above 
  defined 
  before 
  

   incidence. 
  And 
  let 
  

  

  denote 
  the 
  hypothetical 
  entropy 
  of 
  the 
  wave 
  before 
  incidence. 
  

   It 
  is 
  what 
  the 
  entropy 
  would 
  be 
  if 
  K 
  x 
  and 
  K 
  2 
  were 
  the 
  

   principal 
  intensities. 
  

  

  After 
  incidence 
  let 
  s 
  become 
  s 
  r 
  , 
  and 
  s 
  x 
  become 
  s^. 
  And 
  

   similarly 
  the 
  entropy 
  of 
  the 
  resonator 
  shall 
  be 
  S 
  before 
  and 
  

   S' 
  after, 
  incidence. 
  

  

  Now,. 
  as 
  we-have 
  seen, 
  ,, 
  (/K 
  2 
  ) 
  = 
  0. 
  But 
  

  

  We 
  will, 
  following 
  Planck, 
  denote 
  by 
  K 
  3 
  what 
  K 
  x 
  becomes 
  

   after 
  incidence. 
  We 
  have 
  then 
  

  

  8 
  J 
  — 
  S 
  X 
  = 
  log 
  -r— 
  '' 
  ' 
  tit 
  

  

  1 
  l 
  av 
  s 
  bv 
  z 
  dt 
  

  

  1 
  ] 
  c^cV' 
  v 
  2 
  U\ 
  . 
  ia 
  

  

  4- 
  ~ 
  log 
  T 
  3 
  -. 
  — 
  ( 
  K, 
  ^- 
  sm 
  j 
  6 
  

  

  av 
  & 
  bv 
  3 
  ±7tv 
  \ 
  l 
  c 
  2 
  ) 
  

  

  dt. 
  

  

  