32 POPULAR SCIENCE MONTHLY. 



the dark segment there appeared many glowing elongated spots all 

 pointing toward a common circle below the horizon. These came and 

 went with such marvelous swiftness that it was difficult to follow their 

 forms with the eye. Still later, all signs of the aurora disappeared, 

 except the primary arc, which had for a time at its lower edge a faint 

 suggestion of prismatic colors. This rested motionless on the midnight 

 heavens until about two o'clock, when it slowly faded, but before it 

 disappeared it was replaced by a bewildering display of a rayed arc. 



From September 1 to the 9th the temperature steadily fell. On the 

 8th the thermometer registered — 43.1 C. This was the coldest spell of 

 the yeai-, and it was folloAved on tlie 9th and 10th by the most vivid and 

 impressive auroral displays that we saw. The exhibit of the evening of 

 the 10th began in quite the usual way, with a cloudless brightness in 

 the south. Soon there appeared an arc with its ends about 10° above 

 the ice. Under this arc there appeared three fragmental arcs. In the 

 course of an hour the first arc nearly disappeared, leaving only a 

 crescent strip, but under it there were bows more or less elliptical. 

 These vied with each other, alternately brightening and fading, and 



HoBizoNTAL Streamers and Parts of Multiple Arcs. Evening of September 20, 1898. 



vanishing altogether or in parts, until after midnight. At about one 

 o'clock they disappeared suddenly and in their place came', with an 

 electric glow and swiftness, a bewitching array of ragged patches de- 

 scribing four arcs. One hour later these spread over the entire heavens, 

 making a system of quivering, moving streamers, sweeping the skies 

 and illuminating the snows with an effect perfectly bewildering. 



This was the last great aurora that we saw, and it was followed 

 by only one other, on September 20. The night at this time was so 

 bright that the phenomenon was barely visible, but its form was differ- 

 ent from any wliich we had seen. There were two horizontal bands; 

 between these was an imperfect arc, and on l)()tli sides were crescent- 

 shaped patches. The whole display came and went within an hour. 



It is a curioup fact that the auroras usually a])peared about the 20th 

 day of the month. During the long polar night, when the boreal 

 display is at its best, we saw very few exhibits. The phenomenon had 

 little or no effect upon the compass, but it seemed to have some con- 

 nection with tlic storms, for it Avas invariably either preceded or suc- 

 ceeded by violent atmospheric agitation. We did not hear any sounds, 



