BARNARD— SELF-LUMINOUS NIGHT HAZE. 233 



seem to be the only months in which the haze was not observed. It 

 was not seen during the years 1912, 1913 and 1914. The greatest 

 amount of it was recorded in October, 1910, and August, 191 7. 

 The first half of 1910 must not be considered because the haze was 

 not noticed until June and as it was not looked for it may have 

 been present. 



A strict comparison cannot be safely made between the fre- 

 quency of luminous haze and that of the aurora by noting the rela- 

 tive number of nights on which they were visible, because often 

 auroras appear in the presence of bright moonlight in which the 

 luminous haze would not be visible. Nevertheless, it may be im- 

 portant to have even a rough comparison. For this purpose, there- 

 fore, I have collected the following dates on which auroras were 

 seen, which covers the entire period over which the luminous haze 

 has been under observation by me. They are from my own records 

 of the aurora which I have kept here for over twenty years. The 

 dates alone are given. A [ ?] means uncertainty as to whether the 

 observation was of a real aurora. Some of the auroras are of very 

 short duration and hence the apparition of an aurora on the date of 

 an observation of luminous haze may not have been coincident with 

 the latter by many hours. The details of the above auroral records 

 will be published later as a continuation of the two lists already 

 printed in the Astrophysical Journal, Vol. 16, p. 135, 1902 and Vol. 

 31, p. 208, 1910. 



