﻿Smithsonian 
  Report. 
  1929. 
  — 
  Compton 
  

  

  PLATE 
  5 
  

  

  1. 
  Hull's 
  Arrangement 
  for 
  Diffracting 
  a 
  Beam 
  of 
  X 
  rays 
  by 
  a 
  

   Mass 
  of 
  powdered 
  Crystals 
  

  

  2. 
  The 
  Diffraction 
  Pattern 
  Produced 
  when 
  a 
  beam 
  of 
  X 
  rays 
  

  

  Traverses 
  a 
  Mass 
  of 
  aluminum 
  Crystals. 
  (Hull) 
  

  

  3. 
  The 
  Diffraction 
  Pattern 
  Produced 
  when 
  a 
  beam 
  of 
  Electrons 
  

  

  Traverses 
  a 
  Mass 
  of 
  Gold 
  Crystals. 
  (G. 
  p. 
  Thomson) 
  

  

  