LIV GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. 
the manner mentioned above, with y = —0.510 and «& only approximately 
constant during the several intervals; in most cases the values obtained by 
both methods are practically identical. 
If the adopted values of the clock error Hw—Gr. are compared with the 
corresponding values following from the eclipses of Jupiter’s Satellites (Table ce), 
and the differences are grouped by D and R, the mean value, in the sense 
obs.—comp., is —14.82 for D and +13.54 for R, according well with the 
expectation that there would be a greater absorption of light in these high 
latitudes, where the planet’s average altitude is smaller than in Kurope and 
Australia. When the three periods of observation of Jupiter’s Satellites are 
considered separately, the mean difference R—D is always positive; but it 
must be added that the symmetrical division holds good only for the whole 
mass of observations; if the same condition were to be fulfilled for each period 
separately, the curve ought to be shifted about 17° downwards at the begin- 
ning of 1894 and 11° upwards at the beginning of 1895. But during both 
these winters the observations of D were so far less numerous than the ob- 
servations of R that no correction could safely be deduced from this consi- 
deration. For the last winter, where the observations of D are in excess and 
the satellite points are on the whole much less dispersed, the condition of 
symmetry is nearly fulfilled. 
The calculated values of Hw — Gr. M. T. may of course be several 
seconds in error and it is possible that this error may in some places reach 
the amount of +208. An error of 20° or 5’ in longitude represents 1.6 km. 
in latitude 80° and 0.8 km. in 85°. 
Voyage along the Coast of Siberia. 
The astronomical observations taken before the enclosure in the ice have 
all been reduced, not only because the track of the ship in these difficult 
regions has an interest in itself, but also as forming the foundation for the 
determination, by compass bearings, of the situation of numerous islands and 
some points on the continent not to be found on previous maps. 
