106 Notice of the late Aurora Borealis. 



lected itself into two rolls forming a double arch, extending 

 nearly across from one horizon to the other. The northern roll, 

 was smaller than the southern ; but it was impossible to say, 

 which (if either)' was the highest. They were not very dis- 

 tinctly separate, but were considerably or very much blen- 

 ded together, except about the middle of the arch. It be- 

 came more obscure, and broke up into fragments more or 

 less distinct. The western motion of these was perceptible, 

 and by looking at one when about 20 or 25 degrees south 

 of the zenith, I estimated its motion at four degrees in thirty 

 two seconds. About this time, the moon rose among a few 

 clouds in the east. 



Frequently, jets or columns, some apparently pretty 

 near, darted up from the northern light, inclining constant- 

 ly to the west, and becoming more distinctly narrow and 

 straight. 



The light in the north now (half past eight) seemed to be 

 rising higher, and becoming more distinctly an arch. Its 

 height from the northern horizon, I estimated at 16°. It was 

 now pretty still; but presently bright jets began to start up all 

 along its course. These continued to play very brilliant- 

 ly for about half an hour. They commonly rose sud- 

 denly, in bright clusters, sending some of the beams fre- 

 quently as high as twenty-five or thirty degrees — and va- 

 rying their appearance continually, being sometimes cloudy 

 or obscure, and at others very bright and narrow. The 

 coruscations, which had been little observed before, now be- 

 came almost constant, and very beautiful. They seemed to 

 consist of broad flashes of light, extending a great distance, 

 or perhaps the whole breadth of the northern light, rising 

 up very rapidly, and succeeding each other very closely, or 

 as well as I could judge, at intervals of about half a se- 

 cond. 



The northern light rose no higher. The jets continued, 

 but were less frequent, and less tall and bright. The corus- 

 cations were still very perceptible, at 1 1 o'clock, when I re- 

 tired. 



The bases of the jets were sometimes below the horizon, 

 sometimes a few degress above it, particularly in the north. 

 The evening was cool, but not cold, as on the 28th August. 

 The sky was at first clear. Some small clouds were seen in 

 the east before the moon rose, and these gradually approach- 



