﻿Illustrating 
  the 
  asymmetry 
  

  

  of 
  the 
  fringes 
  and 
  of 
  the 
  illumination 
  -curves 
  in 
  

   oblique 
  diffraction 
  by 
  a 
  reflecting 
  surface 
  consisting 
  of 
  two 
  parts 
  (Figs. 
  I 
  

   t« 
  IV) 
  or 
  three 
  parts 
  (Figs. 
  V 
  and 
  VI) 
  in 
  the 
  same 
  plane. 
  

  

  