NO. 17.] THE SLEDGE-EXPEDITION. 611 



Correction of Hicks = +31'0 mm. ME= 0'38 mm. 

 - Gary = + 9'7 mm. = 0'48 mm. 



In February, 1895, on board the Fram, Gary's correction was + 5'0 mm., 

 and in June, 1896, -f 9'7 mm. This gives an increase of the correction of 

 4'7 mm. during 15 months. The comparisons with Hicks during the journey 

 and the stay at the winter-hut are incapable of giving any information as to 

 the corrections of Gary. It is not probable that the change of Gary's correc- 

 tion has been uniform during the 15 months. Aneroids are most liable to 

 change their correction when moved or shaken more or less violently, and 

 to keep their correction unchanged when kept at rest. Starting from this 

 consideration, I have assumed that Gary has had its correction increased 

 during the arduous journey over the rugged ice, when it lay in a kayak on 

 the sledge, and that it was unchanged, or very little changed, during the 

 days when it was not exposed to violent motions. Such time are the resting 

 of the expedition in the "Camp of Longing" from July 1 st to 20 th , 1895, and 

 the stay at the winter-hut from August 23 rd , 1895, to May 19 th , 1896. The 

 journey from the winter-hut to Cape Flora, May 19 th to June 16 th , 1896, 

 was made chiefly by kayak and this mode of transportation would hardly 

 have any appreciable influence upon the correction of the aneroid. From the 

 beginning of the sledge-journey in March, 1895, up to the 27 th May of 

 that year, I have reckoned with a constant correction of 2 mm. for Hicks, 

 which gives a slow rising of the correction for Gary, amounting to one milli- 

 metre. Between May 27 th and July 1 st I have assumed the correction for 

 Gary to be rising from + 6'2 mm. to 8 mm. From July I 8t to 20 th , the 

 correction has been taken constant, -f- 8 mm., in the "Camp of Longing". 

 From July 20 th to August 23 rd , the adopted correction is rising from + 8 mm. 

 to 9'7 mm., and for all the rest of the journey the correction is the -f- 9'7 mm. 

 found at Cape Flora. The rate of change from May 27 th to July 1 st is 

 1-64 mm. per month and from July 20 th to August 23 rd , 1'55 mm. per month. 

 This is practically the same rate during the two parts of the difficult sledge- 

 journeying. 



Professor NANSEN agrees with me in this settling of the question of the 

 corrections of the aneroids. As will be shown further on, the adopted values 

 accord well with the atmospheric pressure found on the Fram and at Cape 

 Flora. 



