[ 196 ] 
N° XXI. 
Extract of a Letter from the Rev. JEREMY BELKNAP, 
containing Obfervations on the Aurora Borealis. 
Dover, New-Hampfhire, March 31ft, 1783. 
nae an it ID you ever, in obferving the Aurora Bo- 
7 realis, perceive a found? I own I once 
looked on the idea as frivolous and chimerical, having 
heard it at firft from perfons whofe credulity, I fuppofed, 
exceeded their judgment; but, upon hearing it repeated- 
ly, and from fome others whom I thought judicious and 
curious, I began to entertain an opinion in favour of it. 
I was ftrengthened in this opinion about two years ago, 
by liftening with attention to the flafhing of a luminous 
arch which appeared in a calm frofty night, when I thought 
T heard a faint ruftling noife like the brufhing of filk. Laft 
Saturday evening I had full auricular demonftration of the 
reality of this phenomenon. About ten o’clock the hemi- 
{phere was all in a glow; the vapours afcended from all 
points, and met in a central one in the zenith: All the 
difference between the fouth and north part of the heavens 
was, that the vapour did not begin to afcend fo near the 
horizon in the fouth as in the north. There had been a 
{mall fhower with a few thunder claps, and a bright rain- 
bow in the afternoon; and there was a gentle weftern 
breeze in the evening which came in flaws, with intervals 
of two or three minutes ; in thefe intervals I could plain- 
ly perceive the ruftling noife, which was eafily diftinguifh- 
able from the found of the wind, and could not be heard 
till the flaw had fubfided. The flafhing of the vapour 
was extremely quick; whether accelerated by the wind I 
cannot 
