342 Prof. Hansteen on the Polar Lights, 



fore attached to the body; but those that are neutralized 

 cannot do it, and have therefore a perfectly free passage. Ac- 

 cording to this hypothesis, magnetism would be nothing but 

 neutralized electricity. It is therefore possible that the aurora 

 consists of such neutralized pairs of molecules which here, as 

 in the completed electric circuit, obey the laws of attraction 

 and repulsion of the magnet. I present this as a simple hy- 

 pothesis, and confess that there still remain various obscuri- 

 ties not easily to be solved. But it is not to be expected that 

 in such an obscure and difficult subject the truth should be 

 discovered in a first attempt. 



Dr. Ksemtz, in p. 212, 213, quotes the descriptions of the 

 southern lights by Cook and Forster, as seen by them during 

 their circumnavigation of the south pole in 1772 — 1775. The 

 astronomers Wales and Bayley, who accompanied Cook in 

 this voyage, express themselves more decidedly on this point, 

 viz. in the work published by the Board of Longitude, enti- 

 tled, "Astronomical Observations, made in the Course of a 

 Voyage towards the South Pole and round the World, in the 

 Years 1772—1775: by Wm. Wales, F.R.S. and Wm. Bayley." 

 London, 1779; from which I will quote the following: 



" Meteorological observations on board the Adventure, by 

 W. Bayley. (P. 209.) 25th Feb. 1773, Lat. 51° 41' S., Long. 

 110° 30' -6, Gr. Decl. 20° 52\ W. — This evening we saw for 

 the first time the southern light ; it was so luminous that one 

 could have read large print by it. (P. 218.) 26th Feb. 1774, 

 Lat. 55° 25' S., Long. 2° 28' E., Declination 9° 25' W.— Seen 

 a southern light, but not very luminous." 



Meteorological observations made on board the Resolution, 

 by W. Wales. 



P. 343, Tuesday, 16th Feb. 1773. " Mr. Pickersgill saw a 

 southern light." 



P. 343. Wednesday, 17th Feb. 1773, Lat. 57° 34' S., Long. 

 83° 23' E. Decl. 40° 40' W. "About 1 o'clock in the morning, 

 Mr. Clerke, who was on duty, told us, that the same phaeno- 

 menon which had been seen the night before by Mr. Pickers- 

 gill, was to be seen in a very luminous state. I got up, and 

 found that it was just the same phaenomenon which we call 

 aurora borealis in England. The natural state of the sky, 

 except in the south-eastern quarter, and at an elevation of 

 nearly 10° round the whole horizon, a white haze through 

 which the stars of the third magnitude could be just distin- 

 guished. The horizon around was covered with thick clouds, 

 from which many streams of a pale reddish light rose, shoot- 

 ing up towards the horizon. These streams did not possess 

 the motion which they are sometimes seen to have in England, 



but 



