2 8 HIRKELANU. THE NORWEGIAN AURORA POLARIS EXPEDITION, 1902 1903. 



At the side of the plan, upon a line which indicates the magnetic meridian, three magnets are 

 drawn one third of their actual size. Their position is here shown in relation to the meridian. 



t is a thermograph which registers the temperature in the observatory. 



The ventilating air, which, as already said, entered the register-room through the partition-wall, S, 

 passed out through the draught-pipe, V, into the open air. As this ventilation was only for the purpose 

 of eliminating the moisture produced by the benzine lamps, and to provide fresh air for the latter, it 

 did not need to be particularly strong. Too strong ventilation is injurious, as with a change in the 

 weather it may occasion a deposit of hoar frost. 



The Observatory for Absolute Magnetic Determinations. 



The house was a frame-house, and, like the register-observatory, was roofed with tarred paper. 



The foundations were dug down to the solid rock, 

 and the walls shored up with earth and stones. 

 As will be seen from the sketch, there is, a door 

 to the north, and a window in each of the other 

 three walls. There is only a single large pillar 

 cemented on to the rock ; but this was so large 

 that the instruments kept their place unchanged 

 all the year through. Their places can best be seen 

 in the sketch (Fig. 18). When one of the magnetic 

 instruments was being used for observation, the 

 magnets were removed from the others, and were 

 then kept in their cases in an empty barrel a little 



Fig. ai. Hut for Absolute Magnetic Measures, .. ,. . ,~. . , ,. 



to the north of the observatory. 1 he theodolite 



and the Coaster Jasai . 



was also removed, if it was not down at the 



dwelling-house at the time. The south window was so arranged that one or more of the four panes 

 could be taken out when observations were being made with the theodolite or the declinator. 



The Dwelling-house. 



This consisted of two rooms. Of these, the south one served as a living-room and office. It had 

 a door leading to the north room, which not only did duty as an anteroom, but also as a workshop 

 and storehouse for various things. The north room had two exits, one to the east and one to the west. 

 The house was built of stone, with wood pannelling inside (frame-work). Between the frame and the 

 stone wall there was a close internal layer of birch-bark, and externally a 6-inch layer of moss. On the 

 roof also there was first a layer of birch-bark, then moss, and on the top of that a layer of gravel; 

 and finally, the whole was roofed with slates. In this way, the house was both substantial and warm. 



The Storehouse. 



This was a little square house with door on the north side. It served as the storeroom for the 

 most necessary of our things, such as food, ammunition, etc., so that, in case of fire, we should not be 

 left without the necessaries of life. Outside the north wall stood the thermometer-screen, (t) It was 

 divided into two compartments, one for the thermometers and one for the registering apparatuses. It 

 was also arranged so that the draught of air could be reduced to a minimum. The air was admitted 

 through holes in the bottom. The draught was reduced when it was snowing, in order to hinder the 

 snow from blowing in and filling the screen. 



