﻿Smithsonian 
  Report 
  1922. 
  — 
  Humphreys. 
  

  

  Plate 
  6. 
  

  

  I. 
  Cirro-cumulus. 
  

  

  (E. 
  E. 
  Barnard, 
  photo.) 
  

  

  2. 
  Cirro-cumulus, 
  with 
  Alto-cumulus 
  Merging 
  into 
  Alto-stratus 
  

   to 
  the 
  Left, 
  from 
  the 
  Ebro 
  Observatory, 
  Tortoso, 
  Spain. 
  

  

  