542 



THE AURORA BOIIEALIS. 



than others, they occasionally fill the whole northern heavens, and are 

 exceedingly vivid, so that it is not strange that ignorant and excitable 

 minds should be filled with alarm at their appearance. The parallelism, 

 however, referred to as apparent in the rays of the separate masses, does 

 not reaily exist, for all evidently converge to a common point, which is 

 near the zenith. This is very striking when the aurora extends far 

 round from the north toward the east and west. Then the sky appears 

 like a great dome, towards the top of which the streamers dart up, from 

 all the parts of the luminous horizon. 



4. Accompanying the streamers, and apparently rolled along and 

 supported by them, may sometimes be seen waves of light called ^'■au- 

 roral leaves^'' and also, on account of their irregular motion and fantas- 

 tic shapes, ^'■merry dancers.'''' These, to the highly excitable imagina- 

 tions of the fearful and superstitious, have suggested the forms of armies 

 engaged in deadly conflict widi each other, so that their hurried and con- 

 fused movements, the fire-flashes of their arms, and the streams of the 

 blood of their slain could be distinctly seen, and even the dying echos 

 of their musketry and artillery could be faintly heard. And hence auro- 

 ras unusual for their brilliancy, intensity of color, and irregular move- 

 ments have been regarded by them as portentous of sanguinary and de- 

 structive war. 



5. It very frequently happens that the streamers, which shoot up to- 

 wards the zenith, converge in a bright patch, or ^'■corona ;" which in ita 

 turn, becomes a centre from which the most brilliant flashes of various- 

 colored light are sent forth : and which, therefore, becomes, if possible, 

 on oI;)ject of greater interest and wonder than any other part of the great 

 auroral display. The corona is therefore not only the point towards 

 which the streamers from the northern semicircle of the horizon tend, 

 but also a centre of emanation in all directions ; but, especially towards 

 the south, if there be an auroral arch in that direction. It is generally 

 an object of exceedingly great beauty and splendor. Some coronas have 

 been witnessed of a uniform rose-red color, and others have been seen 

 to flash forth alternate sectors of red, white, and yellow light. The po- 

 sition of the corona, it is worthy of remark, is uniformly found to be 

 in or near the elevated pole of the dipping needle, which, for the inhab- 

 itants of Gettysburg, would be about 2° east, and ISI'^ south of the 

 zenith. 



6. Another almost constant characteristic of the aurora is the exist- 

 ence of one or more Iwninous arches^ very much resembling cirrus cloud, 

 stretching across the heavens from some eastern point to one near the 

 west. Such an arch was described in the June number of this Jo^urnai? 



