178 Prof. Hansteen on the Aurora Borealis. 
from the surface of the earth, in a direction inclining towards 
the south (an inclination which with us forms an angle of 
about 73°). If then this light occupies the whole northern 
sky, rising more than 17° above the zenith, the rays must pro- 
ceed from under the feet of the observer, although they do not 
receive their reflecting power till they have reached a consi- 
derable elevation, perhaps beyond our atmosphere. It is 
therefore conceivable why we should frequently hear a noise 
attending the northern lights, when the znhabitants of southern 
countries, who see these phzenomena at a distance of several 
hundred miles, hear no report whatever. Wargentin, in the 
15th volume of the Trans. of the Swed. Acad., says that Dr. 
Gisler and Mr. Hellant, two scholars who had resided for some 
time in the north of Sweden, having been so requested by 
the Academy, made a report of their observations on the 
aurora borealis. 
The following is an extract from Dr. Gisler’s account: 
‘«‘ The most remarkable circumstance attending the northern 
lights is, that although they seem to be very high in the air, per- 
haps higher than our common clouds, there are yet convincing 
proofs that they are connected with the atmosphere, and often 
descend so low init, that at times they seem to touch the earth it- 
self, and on the highest monntains they produce an effect like @ 
wind round the face of the traveller.” He also says that he 
himself as well as other credible persons, ‘* had often heard the 
rushing of them, just as if a strong wind had been blowing (al- 
though there was a perfect calm at the time), or like the whizzing 
heard in the decomposition of certain bodies during a chemical 
process.” It also seemed to him that he noticed “a smell of 
smoke or burned salt.” ‘ I must yet add,” says Gisler, “ that 
people who had travelled in Norway, informed me they had 
sometimes been overtaken on the top of mountains by a thin 
fog, very similar to the northern lights, and which set the air 
in motion; they called it Sz/debleket (Haring’s lightning), and 
said that it was attended by a piercing cold, and rendered 
breathing difficult.” Dr. Gisler also affirms that he heard re- 
peatedly “ofa whitish gray cold fog with a greenish tint, which, 
although it did not prevent the mountains from being seen, yet . 
somewhat obscured the sky, rising from the earth, and changing 
itself at last intoa northern light; at least such a fog was fre- 
quently the forerunner of this pheenomenon.” 
Capt. Abrahamson, in the publications of the Scandinavian 
Literary Society, has also collected several observations of 
noises that were heard with the northern lights. I know my- 
self several persons who have witnessed it, and shall make use 
of their observations on the first opportunity. 
XXVI. Con- 
© 
