LVIII §GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. — [NORW. POL. EXP. 
tangent to one of them, and when the edge used is apparently the same (e. g. 
the upper) in both positions, they are really different; thus the horizontal 
point of the circle will be different in the two positions, unless the semidia- 
meter is given a constant correction. In the mean the effect will of course 
be eliminated. 
Both the travellers carried pocket chronometers which will be designated 
in the following by I and II. The first, carried by Nansen, was marked 
“Johannsen 6455”, the other, carried by Johansen, was denoted in the jour- 
nals of the Fram as ,,No. 19787”; it was Nansen’s watch from the Green- 
land expedition. Both were carefully compared with chronometer Hohwii by 
Lieut. Scott-Hansen during several months before starting, and under varying 
conditions which differed, however, considerably from those of the sledge 
expedition. The mean daily rate of I on Mean Time during periods of a 
week or more varied between 3.89 and 5.82 fast, of II between 1.82 and 3.83 
slow. During the days February 26—March 6, including the first trial expedi- 
tion, the rate of Il was —2.°42, and during the next eight days which were 
spent on board, it was —2.835. Watch I was not compared with Hw on 
returning to the ship (Nansen returned on March 3, Johansen on March 4) 
but the mean rate during Febr. 26—March 14 was +5.80. The relative rate 
of I—II was thus +7.:4. During the expedition it was more irregular, but 
on the average greater, about 10—13 seconds. Both watches appear to have 
been going faster, but I more than II. 
It happened several times that one of the watches ran down. Unfortu- 
nately it happened also once, when the working day of the men had been 
longer than that of the watches, that both ran down. The astronomical obser- 
vations between which the stopping occured (1895 April 12) were 5 days apart. 
As the weather was clear and the ice good, the dead reckoning for this inter- 
val will probably not be much in error; but the drift of the ice is of course 
unknown. 
There is, however, another difficulty which for a certain period of the 
expedition is more serious than the stopping of the watches. During the 
months of April and May all altitudes were measured with the sextant, and, 
with one exception, from the natural horizon. In the afternoon of April 2 
a series of 6 altitudes was taken, the first three with glass horizon, the rest 
with natural horizon. The two sets give a difference of nearly ten minutes 
