ANALYSIS OF THE IONOSPHERE 



485 



Attempting to supply an answer to this question, I point out that 

 in such part of the theory as I have thus far given, there is nothing 

 corresponding to absorption. This is because the electron-current 



15 16 



TIME OF DAY 



18 



19 



Fig. 15 — Trend of the critical frequencies and of the minimum echoed frequency 

 as a fadeout proceeds. (Berkner.) 



{le in the former notation) is in quadrature with the electric vector 

 in the waves, being thus a "wattless current." This in turn is because 

 we have assumed each electron to be entirely free, oscillating in the 



