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BELL SYSTEM TECHNICAL JOURNAL 



and spots on terrestrially disturbed and quiet days shows a maximum 

 and minimum, respectively, about 13° west of the center (one day 

 past) ; see Fig. 2. These curves are interpreted as indicating that the 



SUN SPOTS 



DARK FLOCCULI (h) 



BRIGHT FLOCCULI (H) 



EAST 

 LIMB 



CENTRAL 

 MERIDIAN 



WEST 

 LIMB 



Fig. 2 — Distribution across the solar disc of solar phenomena on 

 terrestrially disturbed and quiet days. 



most probable position of flocculi and spots on disturbed days is 13° 

 west of the center of the solar disc and that on quiet days it is other 



