228 ELECTRICITY OF THE ATMOSPHERE AND AURORA BOREALIS. 



of September, while the Sophie was anchored at Southgatt, that I could 

 carry this project into execution. 



Having made my electrometer more sensitive, I went, on the day 

 above mentioned, between 11 o'clock and noon, to an island situated at 

 the moijth of the Southgatt, and established my instrument on the high- 

 est point of the island, GOO feet above the level of the sea. Notwith- 

 standing these precautions I still obtained no certain result. This was 

 possibly on account of the violence of the wind, which produced oscilla- 

 tions in the electrometer, but other observations made on the 7th of 

 October at King's Bay were equally unsuccessful. 



Although these experiments were too few in number, and too incom- 

 plete to draw from them any positive conclusion whatever, I am con- 

 vinced that this absence of electric manifestation was due to the peculiar 

 constitution of the air in these regions. A glance over the hygrometric 

 observations shows that the air was almost constantly saturated with 

 moistnre, and this moisture did not exist merely in the form of insensible 

 vapor, but also as fog. This circumstance rendered it almost impossible to 

 isolate the instrument, and consequently to obtain the effects of the 

 electricity of tension. We may at least conclude that there is no elec- 

 tricity of tension in northern aerial regions which approximate to a plain, 

 but that the electricity rises through damp air into the higher regions 

 of the atmosphere. I am inclined to believe that observations of the 

 electricity of the air made on level ground will always give negative 

 results. Elevated ground should be chosen, and an instrument which 

 may be sent up into the higher strata of the atmosphere, such as the 

 kite used by Franklin. 



Setting aside these incomplete experiments, which can only be of use 

 as guides for future eflbrts, I pass to the observations upon the aurora 

 borealis. 



During the last days of September the Sophie was anchored at South- 

 gate, a strait lying between the island called Danes Island and the 

 continent of Spitzbergen, at 79° 39' 1" of latitude and 11° 7' of longitude 

 west of Greenwich. The gulf .of which this strait is an outlet is sur- 

 rounded on the north and south by mountains, those on the south about 

 300 meters in height. At the mouth of this gulf lies the island above 

 mentioned; to the east the view is limited by other mountains varying 

 in height. The Sophie w\as anchored close to the shore of Danskow, a 

 little to the northwest of the island, at the mouth of the strait. On 

 returning from the island, where the instruments for the magnetic obser- 

 vations had been deposited, I perceived upon the ridge of the mountain, 

 to the south, a brilliant polar light rising from 10° to 15° above 

 the mountain in undulating rays, distinctly defined, at their base ap- 

 pearing as a diffuse yellowish light, but higher up as vertical orange 

 beams, while at the top they formed a series of sharj) points. The rays 

 had an undulating motion, and the crest of the mountain was covered 

 with a light fog, which the wind was moving from east-northeast to 



