﻿Smithsonian 
  Report, 
  1929. 
  — 
  Wilkes 
  

  

  Plate 
  3 
  

  

  '" 
  ^ 
  M 
  > 
  sa\ 
  

  

  1. 
  A 
  Modern 
  Kerosene 
  heated 
  absorption 
  Process 
  Unit. 
  The 
  Black 
  

   Ball 
  is 
  Placed 
  Within 
  the 
  Cabinet 
  

  

  2. 
  professor 
  Wilkes 
  with 
  the 
  Elaborate 
  Lecture-table 
  Demonstra- 
  

   tion 
  HE 
  Arranged 
  for 
  a 
  popular 
  science 
  lecture 
  

  

  