BARNARD— SELF-LUMINOUS NIGHT HAZE. 227 



is very important that no mistake be made in the identification and 

 I therefore would call attention to the objection to the denser form 

 of cirro-stratus. This photograph, therefore, represents a denser 

 condition of that cloud and would probably obliterate the stars at 

 night. 



In the previous paper (mentioned before) there is a suggestion 

 that the probable passage of the earth through the tail of Halley's 

 comet had something to do with the luminous condition of this 

 haze, because it made its appearance very soon after that event. 

 With the later information there is now no need to call upon the 

 comet for an explanation of the phenomenon. 



Following is given a continuation of my records of luminous 

 haze. The times are Central Standard Time, which is 6'^ o" slow 

 of Greenwich mean time. 



191 1, June 17. Traces of it were suspected before moonrise, 

 but not certain. 



Aug. 28, 10'^ 15™. Masses of it were extending over the bowl 

 of the Great Dipper. They were irregular and very extended to 

 the right and left of the Dipper. The motion was slow, to the right 

 horizontally. At 10^ 35"^ it extended the full length of the Dipper 

 and 15° to the right and 10° to the left of it; visible for some time 

 and feebly luminous ; steady in its light. At 14'' 35™ there was a 

 long, rather bright luminous strip 4° wide extending along the bowl 

 and handle of the Dipper ; horizontal and quite bright. This was 

 perhaps auroral. A few minutes later it had gone. No other signs 

 of aurora. 



Sept. 15, 9'^ 15™. Bright auroral streamers from below the 

 horizon, but no arch. In various parts of the sky there were broad 

 streaks and areas of luminous haze. Several very long, broad 

 strips through the Dipper extending east and west. At 9^" 25" there 

 were thin sheets of it all over the sky, one passing over Brooks' 

 comet which I was photographing, and another one parallel to the 

 first 5° north of it. They extended east and west and were drifting 

 northerly. At 9'^ 55™ there were great streams and areas of it with 

 dark spaces between. There was a little auroral light low in the 

 north. At lo'^ 10"^ the two long masses of haze had drifted north. 

 There were masses of it all over the sky, specially to the south. 



