LI GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. 
coefficient, is apparent from the fact that the relative temperature coefficient 
of Iv—Hw on board is sensibly smaller than the difference between the above 
values of y for Jv 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 a separately for the three intervals by intro- 
duction of the temperature coefficient —0.°189, the mean of the values found 
in Christiania with due regard to weight; that is to say 
aw = daily rate +0.5189 ¢. 
The result was: 
Gr. T. Hw—Gr. Mean Rate t x 
4. 1893 July 18. ...| 20h 0m 49m5()s ioe ue 
9, 189% April5....| 1654 Ad 44 antes oy . a ae 
3. 1895 March 25...| 98 15 39 40 2 a pee 1, 487 
4. 1896 Aug. 22....|] 21 0 35 33 eed 12, 246 1. 835 
It may have some interest to compare the mean rate of Hw with those 
of Kt and Jv for the same intervals : 
Kt—Gr. Rate Iv—Gr. Rate 
tl. — 
Boil meee aQegr7 ||| eer ee a dens 
9, —1 57 52 40 : 
ai eae OEE 5 a Wea 
4. Re —1. 63 79 31 +2. 08 
