OBSERVATIONS UPON THE ELECTRICITY OF THE ATMOSPHERE 

 AND THE AURORA BORI^^ALIS, MADE DURING THE SWEDISH 

 EXPEDITION OF 1868 TO THE NORTH POLE. 



By Prof. Selim Lemstrom, of the University of Helsingfors, Finland. 



There can be no savant now living who is not convinced that polar 

 light is a phenomenon due to electric action in the upper regions of the 

 atmosphere. Of the two theories which have been advanced to explain 

 the phenomenon, one of which seeks its origin exclusively in variations in 

 the intensity of terrestrial magnetism, the other in the electricity of the 

 air, the former must give place to the latter, since there are very many 

 convincing proofs in its favor. Unhappily, our knowledge of the electric 

 state of the atmosphere in high polar regions is very limited; could it 

 be extended, all doubts which now exist in regard to the subject would 

 probably disappear. The attempts made to discover the nature of 

 atmospheric electricity in the regions of the extreme north, have in gen- 

 eral given only negative results, with the exception, however, of the re- 

 searches made in the neighborhood of Bossekop by French savants, who, 

 by sending up a kite or an arrow, attached by a conducting wire to an 

 electroscope, to a vertical height of from 30 to 40 yards, have proved 

 the constant presence of positive electricity ; but, these observations are 

 too few in number, and were made in a latitude not sufficiently high to 

 be conclusive. 



I. One of the most important of my objects in the physical researches 

 of the expedition of 18G8 was the study of the phenomena relating to the 

 electricity of the atmosphere ; but notwithstanding all my care, I ob- 

 tained only negative results. As I am convinced that in every case T 

 could account for my want of success, I will briefly describe the experi- 

 ments I attempted, in order to pass to the observations I had occasion to 

 make in regard to the aurora borealis. 



The first experiment, made on the 26th and 28th of August, 18G8, on 

 a narrow tongue of land at Kobbe Bay, by means of the electrometer, 

 gave no result, although the observations were made several times a 

 day, and even at night, at the same time that I observed the magnetic 

 instruments. Expecting to find the cause of these negative results 

 either in the insensibility of the instrument or in the nature of the lo- 

 cality, which, closed on three sides by mountains, was open only on the 

 side toward the sea, I determined to modify my instrument, and to look 

 for a more open place for my observations. It was not until the 28th 



