LII 



GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORVV. POL. EXP. 



coefficient, is apparent from the fact that the relative temperature coefficient 

 of Iv Htv on board is sensibly smaller than the difference between the above 

 values of y for Iv and Hw, both in 1893 and in 1896. 



Some trials were made in order to throw some light on this point. If 

 the values of the clock error as determined 1) by the telegraphic signals be- 

 fore and after the expedition, 2) by the two solar eclipses observed on board, 

 and 3) by the eclipses of Jupiter's Satellites and by Lunar Distances, are 

 called 1) the signal points, 2) the solar points, and 3) the satellite points res- 

 pectively, the problem to be solved may be expressed thus : To draw a curve 

 going exactly through the signal points, through or very near the solar points 

 and among the satellite points which are rather widely dispersed, especially 

 during the two first winters ; the whole time with due regard to temperature. 



As it happened that the mean temperature in the intervals between the 

 signal and the solar points was somewhat different, an attempt was first made 

 to determine the constant term x separately for the three intervals by intro- 

 duction of the temperature coefficient 0. 9 189, the mean of the values found 

 in Christiania with due regard to weight; that is to say 



x = daily rate -f0. 8 189 t. 



The result was : 



It may have some interest to compare the mean rate of Hw with those 

 of Kt and Iv for the same intervals : 



