Smithsonian Report, 1936. — Eve 



PLATE 2 



1. REFLECTIONS OF RADIO WAVES FROM THE APPLETON OR F REGION. 



G is the ground or original signal. Fi, Fj, Fs . . . are successive signals echoed from the stated region or 

 after repeated reflections from ground and ceiling. 



2. There are Echoes Shown From Both E and f Regions. 



The lower curve gives a time-scale of 1,110 cycles a second. Figs. 1 and 2 are due to the courtesy of 



Prof. E. V. Appleton. 



