﻿processes 
  and 
  Planck's 
  Theory, 
  231 
  

  

  Let 
  now 
  the 
  plane 
  of 
  the 
  paper 
  be 
  that 
  of 
  the 
  wave, 
  and 
  

   let 
  the 
  dotted 
  line 
  0^ 
  be 
  the.directioii 
  of 
  the 
  resonator 
  axis 
  

   which 
  makes 
  the 
  angle 
  6 
  with 
  the 
  normal. 
  

  

  Let 
  OP 
  be 
  the 
  projection 
  of 
  Oz 
  on 
  the 
  plane, 
  OR 
  a 
  line 
  in 
  

  

  the 
  plane 
  perpendicular 
  to 
  OP, 
  and 
  therefore 
  to 
  Oz. 
  Also 
  let 
  

   OK 
  denote 
  the 
  principal 
  direction 
  corresponding 
  to 
  the 
  in- 
  

   tensity 
  K. 
  

  

  Then 
  the 
  angle 
  KOP 
  = 
  o> 
  

  

  and 
  PO^ 
  =|-0. 
  

  

  K 
  x 
  is 
  the 
  intensity 
  of 
  vibration 
  in 
  OR, 
  

   Kg 
  „ 
  „ 
  ,, 
  OP. 
  

  

  The 
  electric 
  force 
  due 
  to 
  the 
  vibrations 
  K 
  2 
  in 
  OP 
  is 
  per- 
  

   pendicular 
  to 
  OP, 
  that 
  is 
  in 
  OR, 
  and 
  is 
  therefore 
  perpen- 
  

   dicular 
  to 
  Oz. 
  Therefore 
  the 
  vibrations 
  K 
  2 
  have 
  no 
  electric 
  

   force 
  in 
  Oz. 
  They 
  do 
  not 
  affect, 
  and 
  are 
  not 
  affected 
  by, 
  the 
  

   resonator. 
  If 
  ^K 
  denotes 
  for 
  any 
  K 
  the 
  change 
  in 
  it 
  due 
  to 
  

   incidence 
  on 
  the 
  resonator, 
  ^K 
  2 
  = 
  0. 
  

  

  On 
  the 
  other 
  hand 
  the 
  vibrations 
  in 
  OR, 
  whose 
  intensity 
  is 
  

  

  -K 
  1? 
  have 
  electric 
  force 
  in 
  OP, 
  which 
  makes 
  the 
  angle 
  — 
  — 
  6 
  

  

  with 
  the 
  axis. 
  Therefore 
  a 
  part 
  of 
  the 
  energy 
  of 
  these 
  

   vibrations 
  is 
  absorbed 
  by 
  the 
  resonator, 
  and 
  lost 
  to 
  the 
  wave. 
  

  

  Q 
  2 
  

  

  And 
  this 
  part 
  is 
  in 
  time 
  dt, 
  — 
  — 
  - 
  K 
  L 
  sin 
  2 
  dt 
  dil 
  (p. 
  461, 
  

   -equation 
  (36)). 
  47rv 
  

  

  It 
  should 
  be 
  noted 
  that 
  

  

  3cV 
  3 
  c 
  2 
  

  

  4:7TV 
  -±7T 
  V 
  w 
  

   ■±1T 
  

  

  where 
  X 
  is 
  the 
  wave-length. 
  Now 
  av 
  has 
  been 
  assumed 
  to 
  

  

  