Observations of Aurora. 



108 



August 1883. 



The preceding tables are compiled from the journal of hourly auroral observations. 



The form of the aurora is expressed by Roman figures, according to Weyprecht's 

 scale, viz : — 



I. Arch. V. Patches, or undefined light. 



II. Streamers. VI. Dark segment. 



III. Stri^. YII. Polar light. 



IV. Corona. VIII. Sheaves. 



The brilliancy is shown by Arabic numerals on the scale 1 — 4, 1 being very faint, 

 and 4 very bright, aurora. 



The letter A denotes that aurora was observed, but that it was more or less concealed 

 by clouds. 



At hours when no aurora was recorded the state of the sky is shown by the letters 

 b, c, 0. 



The dotted lines mark the beginning and end of twilight. 



