﻿46 
  

  

  Dr. 
  L. 
  Silberstein 
  ou 
  Light 
  Distribution 
  

  

  The 
  curves 
  in 
  fig. 
  4 
  (which 
  could 
  also 
  be 
  taken 
  from 
  

   those 
  of 
  fig. 
  3) 
  are 
  drawn 
  * 
  directly 
  according 
  to 
  this 
  table, 
  

   with 
  v 
  as 
  abscissae 
  and 
  A 
  2 
  + 
  B 
  2 
  as 
  ordinates, 
  and 
  thus 
  

   represent 
  the 
  intensity 
  at 
  selected 
  places 
  of 
  the 
  focal 
  plane 
  

  

  Fig. 
  4. 
  

  

  as 
  a 
  function 
  of 
  the 
  aperture 
  of 
  the 
  lens. 
  It 
  will 
  be 
  

   remembered 
  that 
  v 
  is 
  proportional 
  to 
  the 
  square 
  of 
  the 
  

   aperture, 
  viz., 
  by 
  (20), 
  

  

  / 
  rn 
  2 
  /h\ 
  2 
  r 
  

  

  (25) 
  

  

  Thus, 
  for 
  example, 
  if 
  n 
  = 
  1/5 
  and 
  r 
  = 
  5 
  10 
  6 
  \, 
  then 
  

   ( 
  u=1000^- 
  ) 
  . 
  The 
  uppermost 
  curve 
  in 
  fig. 
  4 
  corresponds 
  

  

  * 
  My 
  thanks 
  are 
  due 
  to 
  Mr. 
  W. 
  Widigjor 
  for 
  the 
  execution 
  of 
  both 
  

   sets 
  of 
  curves. 
  

  

  