August 23, 1 88 3 J 



NA TV RE 



397 



is necessary to work with patience and in co-operation 

 with others, as the labour is one demanding both time 

 and exhaustive study. Anton Stuxberg 



Gothenburg Museum 



DR. TROMHOLT'S AURORAL OBSERVATORY 

 AT KAUTOKEINO 



WE are indebted to Dr. Sophus Tromholt for the 

 photograph from which our engraving has been 

 made of his auroral observatory at Kautokeino in Fin- 

 marken, Norway. 



The Norwegian savant has, as may be remembered 

 from his communications to Nature, during last winter 

 sojourned in Lapland for the study of the aurora borealis, 

 simultaneously with which observations of this remark- 

 able phenomenon have been made at the Norwegian 

 and Finnish Circumpolar Stations at Bossekop and 

 Sodankyla. 



Dr. Tromholt writes :— " Since September last I have, 

 for the sake of the aurora borealis, been residing here in 

 North Finmarken (69 N. lat., 23° E. long.), in a zone 

 therefore where the aurora? attain their maxima, and 

 where the phenomena, consequently, are so frequent and 

 on such a scale that there cannot be a question of 

 selecting and analysing one in particular. 



" My winter sojourn here has two objects in view, viz. 

 firstly to frame a pendant to the observations of the 

 aurora borealis made at Bossekop, 1838-39, by the French 

 Commission du Nord under Lottin and Bravais (' Voyages 

 en Scandinavie,' &c), and, secondly, by means of alti- 

 tudinal measurements corresponding with those being 

 nude at the Norwegian Meteorological Station at Bosse- 

 kop, to procure sufficient materials for fixing the parallax 

 of the aurora borealis. I choose the remote Kautokeino 

 for my observatory for several reasons, viz. : that the 

 place is almost due south of Bossekop, while the distance 

 between the two is very nearly a degree, a distance which 



Auroral Observatory at Kautokeino. 



is exactly suited to the theory I have formed of the height 

 of the aurora borealis — 150 kilometres ; and also because 

 it possesses a remarkably free horizon and an inland 

 climate insuring favourable weather conditions. 



" As previously stated, observations are made simul- 

 taneously here and at Bossekop on a common prearranged 

 plan, and measurements made in the same vertical plane 

 by the so-called auroral theodolite constructed by Prof. 

 Mohn. A similar arrangement has also been made with 

 the Finnish station at Sodankyla, which is, however, situ- 

 ated at a great distance from this place, and in a direc- 

 tion somewhat unfavourable (about 45 S.E.). We shall 

 not of course be able to compare notes before the spring, 

 so I am unable at present to give the final results of my 

 observations ; but judging by own researches here I feel 

 convinced, in spite of scientists' assertions to the contrary, 

 that the height of the aurora borealis may be measured 

 by the method I advocate, and that from the observa- 

 tions made at these three stations we shall obtain the 



materials required for the solution of a problem hitherto 

 deemed an insoluble one. 



"The photograph which I forward you shows the little 

 ' scientific temple' I have raised in these lonely tracts, which 

 have hitherto only seen Lapps and reindeer. In the centre 

 stands my most important instrument, viz. a combination 

 of the auroral theodolite and the passage instrument, fixed 

 on a stone column and inclosed in a small wooden box, 

 the upper half of which may be lowered at will. Here 

 are, besides the necessary apparatus for meteorological 

 observations, also to be found every requisite instrument 

 and appliance required for my researches, such as chrono- 

 meters, spectroscopes, lanterns, &c. Between them all 

 stands the writer himself, clad in the tasteful summer 

 costume of a Lapp, viz. pointed leather shoes, breeches 

 twisted around the leg at the ankle, the blue frock orna- 

 mented with red and yellow borders ; and to crown it, the 

 smart cushion-shaped cap. 



" I have several times attempted to photograph the 



