76 On the sound which accompanies the Aurora Borcalis. 



heard several times a quick whispering sound simultaneously 

 with the motion of the rays over my head." 



Professor Hansteen then adds the following observations : 

 " The polar regions being in reality the native country of the 

 polar light, we ought to be peculiarly interested in obtaining 

 any additional information on the natural history of this re- 

 markable phenomenon ; and we have so many certain accounts 

 of the noise attending it, that the negative experience of south- 

 ern nations cannot be brought in opposition to our positive 

 knowledge. Unfortunately, we live, since the beginning of 

 this century, in one of the great pauses of this phenomenon, 

 so that the present generation knows but little of it from per- 

 sonal observation. It would, therefore, be very agreeable to 

 receive, from older people, observations of this kind, made in 

 their youth, when the Aurora Borealis showed itself in its full 

 splendour. It can be proved mathematically, that the rays of 

 the Northern Lights ascend 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 1 7° above 

 the zenith, the rays must proceed from under the feet of the 

 observer, although they do not receive their reflecting power 

 till they have reached a considerable elevation, perhaps beyond 

 our atmosphere. It is, therefore, conceivable, why we should 

 frequently hear a noise attending the Northern Lights, when the 

 inhabitants of southern countries, who see these phenomena 

 at a distance of several hundred miles, hear no report what- 

 ever. Wargentin, in the 15th volume of the Transactions of 

 the Swedish Academy, says, that Dr Gisler and Mr Hellant, 

 who had resided for some time in the north of Sweden, made, 

 at the request of the academy, 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, 

 perhaps higher than our common clouds, there are yet con- 

 vincing proofs that they are connected with the atmosphere, 

 and often descend so low in it, that at times they seem to tough 

 the earth itself; and on the highest mountains they produce 



