234 Ml* William Sturgeon on the Aurora Borealis. 



aurora till about nine o'clock ; but, at that time, he " ini mediately- 

 perceived, towards the south and south-west quarter, that, though the 

 sky was clear, yet it was tinged with a strange sort of light ; so that 

 the smaller stars were scarce to be seen, and much as it is when the 

 moon of four days old appears after twilight. I perceived, at the 

 same time, a very thin vapour to pass before us, which arose from 

 the precise east of the horizon, ascending obliquely, so as to leave 

 the zenith about fifteen or twenty degrees to the northward. But the 

 swiftness wherewith it proceeded was scarce to be believed, seem- 

 ing hot inferior to that of lightning, and exhibiting, as it passed on, 

 a sort of momentaneous nubecula, which discovered itself by a diluted 

 and faint whiteness ; and was no sooner formed, but before the eye 

 could well take it, it was gone, and left no signs behind it. Nor was 

 this a single appearance ; but for several minutes, about six or seven 

 times in a minute, the same was again and again repeated, these 

 waves of vapour, regularly succeeding one another, and at intervals 

 nearly equal, all of them in their ascent producing a like transient 

 nubecula. By this particular we were at first assured, that the 

 vapour we saw became conspicuous by its own proper light.'' 



In this noted aurora, there was no light seen in the north till about 

 eleven o'clock. " On the western side of the northern horizon, viz., 

 between west and north-west, not much past ten o'clock, I observed," 

 says our author, " the representation of a very bright twilight, con- 

 tiguous to the horizon, out of which arose very long beams of light, 

 not exactly erect towards the vertex, but something declining towards 

 the south, — which ascending by a quick and undulating motion to a 

 considerable height, vanished in a little time, whilst others, at cer 

 tain intervals, supplied their place. But, at the same time, through 

 all the rest of the northern horizon, viz., from the north-west to the 

 true east, there did not appear any sign of light to arise from, or 

 join to, the horizon, but what appeared to be an exceedingly black 

 cloud seemed to hang over all that part of it ; yet it was no cloud, 

 but only the serene sky, more than ordinary pure and limpid, so that 

 the bright stars shone clearly in it." 



The Doctor next mentions " two laminoe, or streaks" of light, 

 " lying in a position from the north by east to the north east, and 

 wei'e each about a degree broad ; the undermost about eight or nine 

 degrees high, and the other about four or five degrees over it : these 

 kept their places for a long time, and made the sky so light, that I 

 believe a man might easily have read an ordinary print by the help 

 thereof." And again : " It being now past eleven of the clock, and 

 nothing new offering itself to our view but I'epeated phases of the 

 same spectacle. I observed, that the two lamince or streaks, parallel to 

 the horizon, had now wholly disappeared ; and the whole spectacle 

 reduced itself to the resemblance of a very bright crepusculum, 

 setting on the northern horizon, so as to be brightest and highest 



