116 



GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. 



The above values of LT I have been computed with 90 = 86 6' .2, which follows from the 

 meridian altitude. It is apparent from the increasing values of LT I with increasing differential 

 quotients that a diminution of y will give better agreement Introducing Jh and 4<p as before, 

 the mean of the four observations gives 



Watch I lh 5m a.m., LT-1 = 6>> 2m 21" + 0.281 4<p + 1.024 Jh. 



For 4h there is no other choice than using the former value ; d<f at noon had perhaps 

 the same value, but the latitude being a little higher in the morning before the departure, it 

 has been assumed that f was 86 0', or 4y = 6'.2. The result is then : 



LT-I = 6h 9m 37s. 



The bearings by compass have been calculated by means of these values. 



These observations were taken shortly after the stopping of both watches. If x is the 

 diminution of east longitude from April 8, 8 a.m., until April 13, 7 a.m., and y the change of 

 watch I caused by the stopping (including its acceleration during the time it was going), the com- 

 bination of the two days gives the equation 



31m.9 _ x - y = 6 h 9m.6 



y = - 37^.7 - x. 



The course set on April 8 and followed during the days following as nearly as hindrances 

 permitted, was S 22 W by compass, or, with magnetic declination 45 E, S 67 W. The dis- 

 tance made during the three days of travelling included in this interval, was estimated by 

 Nansen to be 9 Norwegian sea-miles, or 36 minutes of a great circle, which would give 14' differ- 

 ence of latitude, and nearly 8 difference of longitude. As the course was not, of course, recti- 

 linear, a reduction is necessary, and the latitudes observed show that the reduction in this 

 direction is so considerable that the drift of the ice must have had something to do with it. 

 How the drift has worked in the other direction cannot be decided by this consideration; the 

 assumption of a considerable reduction, viz. from 8 to about 5, for the longitude also, has been 

 made mainly because the retaining of the 8 would imply a greater acceleration of watch I for 

 the rest of the summer than seems likely from other observations. The value y= 57 m 30 s d, 

 given on p. Ill, would correspond to the change of longitude 



x = 19m.8 + J or nearly 5 + ^/. 

 The E. Long, on April 13 should then be 91.5 - 4. 



1896, April 18. Bar. 29.94 in., Therm. - 26. 



The morning observations were made during a journey commencing on April 17, at 7.5 p.m.. 

 and ending on April 18, at 10 a.m., consequently about 4 hours before reaching the camping-place 

 where the meridian altitude was taken. The latter gives the N. Lat. 85 38'. The course being 

 now S by compass, the morning altitudes were reduced with <f = 85 40'. The mean of the 

 three results is 



Watch I Oh 21m a .m., LT-I = 5'' 36 4" - 0.022^ + 0.883 4h. 



