THE LITERARY 



OF THE LINN^AN ASSOCIATION OF PENNSYLVANIA COLLEGE. 



Vol. in. SEPTEMBER, 1847. No. 11. 



THE AURORA BOREALIS. 



This splendid phenomenon, tliough often witnessed and much ad- 

 mired, has not, on that account, been divested of any of its wonderful 

 and interesting character. Though many facts have been accumulated 

 concerning it within the last century, its nature still remains a great 

 mystery. The ignorant still view it with terror, as fore-shadowing some 

 terrible calamity ; and philosophers, although satisfied that it is a phe- 

 nomenon forcing its luminous characters upon the attention of the ob- 

 server according to natural laws, are yet divided in opinion as to its 

 cause. 



Some of these opinions, in connection with its leading characteris- 

 tics and facts, it may not, at this time, be uninteresting to present. 



/. Its great outline' features. 



1. It, sometimes, presents itself to us, in the northern horizon, mere- 

 ly as a diffused light, varying in height and brilliancy, and resembling 

 the light of approaching day. Hence it has been called the '■'■jyorthern 

 Dawn,''^ the ^^JYorthcrn Lights,''^ or the ^^Jlurora Borealis?'' For a simi- 

 lar reason, that, which is occasionally witnessed in high latitudes in the 

 Southern Hemisphere, has been called the "Aurora Australis." 



2. At other times, the diffused light is accompanied by a dark mass, 

 resembling a lank of vapor or of thin-cirrus cloud lying on and skirting 

 the horizon, from behind and above which the light seems to proceed. 



3. More frequently, however, broad masses of luminous matter, in ap- 

 parently parallel lines, are seen to dart up, at various points, from be- 

 hind this nebulous mass towards the zenith. These masses, called 

 '■'Streamers.?'' are at different times, of various colors, such as white and 

 the different shades of red, yellow, and rarely blue. It is not unusual 

 to see them white near the horizon, and red in their upward path. Al- 

 though they generally radiate from some points with greater brilliancy 



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