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BELL SYSTEM TECHNICAL JOURNAL 



of amplitudes toward the right side of these sections. Keeping in 

 mind also the skewing inherent to this system of presentation during 

 transient periods, we are able to trace the movement of minima, as 

 illustrated previously in Fig. 17 w^hich was taken from a different 



Fig. 19 — Plotted curves, condensing a long band fading record so as to bring out the 



effect of selective fading 



record. The relative position of these minima gives us an interesting 

 insight into the nature of the night-time transmission path. 



From records covering frequency ranges up to 4,500 cycles in 

 width the positions of major minima along the frequency axis have 



