416 P- Fr.EUCHEN. 



who have had to take observations when on loose snow will doubtless 

 have experienced this particular difficulty. 



The theodolite itself worked, as already mentioned, admirably, 

 which is the more to be appreciated since it was subjected, on this trip 

 as on previous occasions, to rough usage, the sledge on which it was 

 stowed upsetting or rolling over, or falling down hollows or channels in 

 the ice etc. One such accident, however, did involve some slight damage 

 to the instrument. On the 17th of June, when we were in Independence 

 Fjord, I had started out over a small island in order to take observations. 

 When close up to the island I fell down a fissure which was hidden by 

 the snow above, and filled below with a slushy mess of snow and water. 

 I had some difficulty in getting out again, and while endeavouring to 

 extricate myself I dropped the theodolite and had to go down after it 

 again. It took me some little time to find it ; so that the instrument was 

 left lying at the bottom for the space of twenty minutes or thereabout. 

 After this, it was found that the excentricity for the vertical circle had 

 altered a little, while some black smudges had appeared on the scale 

 of the horizontal, rendering it difficult to read in places. 



I should also mention that all the observations after reaching Zig- 

 zag Valley were carried out while suffering more or less from snow blind- 

 ness, which troubled me a great deal, and which must doubtless have 

 considerably affected the accuracy of the observations. 



Our determinations of longitude are unfortunately far from being suf- 

 ficiently accurate. The station was originally supplied with two ob- 

 servation chronometers made by Carl Ranch, Copenhagen, marked A 

 and B. Observations were made throughout a long period during the 

 winter of 1910 — 11 and also later, as to the correctness of their movement; 

 as ill-luck would have it, however, a servant unacquainted with such 

 instruments, to whom the task of winding them had been entrusted in 

 my absence, forgot this duty, and on finding that the clocks had stopped, 

 opened them and endeavoured to repair the omission by coercing the 

 interior with a penholder. After this, the one marked B, which was 

 the better of the two, refused to go at all. 



Chronometer A, the movement of which had been fairly accurately 

 determined by a series of observations at the station, we took with us 

 on the expedition, and on the way from Thule to the last settlement 

 I carefully noted the inevitable alteration occasioned by the journey. 

 Unfortunately this instrument exhibited one fatal weakness : the slightest 

 alteration of temperature stopped it at once. The cessation of movement 

 might sometimes be of but a moment's duration; it occurred, however, 

 almost invariably whenever the instrument was taken out for purposes 

 of observation, a thing which can hardly be avoided. We then tried 

 making the observations with an ordinary watch, but the mere compari- 

 son of the chronometer with this, though made in the tent in the evening, 

 generally sufficed to stop the movement again, and this despite the 



