Survey of Northeast Greenland. 289 
watch, which was assigned to Bisrrup, was included in the daily 
clock comparisons. 
In order to protect our watches against the cold, we carried them 
on our breasts in little bags hung round our necks. 
On sledge trips the duration of the working day varies a good 
deal. The wish to exploit favourable weather conditions or to get as 
far as a certain point, unexpected hunting, damage to our sledges or 
other delays may cause the working day to be extended over a period 
of thirty to forty hours. Under conditions of this kind the watches 
are very liable to stop. In order to diminish this risk we wound 
them twice daily, which means proved very effective and prevented 
the stopping of our watches. 
The watches were compared once a day and their relative rate 
promptly computed. From the watch rate journal it appears that 
they maintained a fairly regular rate; only watch K, used as an 
observation watch, has on a single occasion, from 13/IV—15/IV, shown 
marked irregularities amounting to about 10$. 
The ten sledges which took part in the great sledge trip of 1907 
were divided into four parties, each with their particular cartographic 
task. According as each party separated from the rest, the clock 
comparison had to be abandoned in the case of the watch belonging 
to that party. The first party (Bisrrup and RING) turned back at the 
Mallemukfjældet 80°9 on April 22nd; the second party (G. Тнозтвор 
and WEGENER) turned back from Amdrup’s Land 80°43’ on April 26th; 
and finally the two remaining sledge parties parted company on 
May Ist, west of Nakkehoved, 81°43’. 
The chronometer 57508 was lost with MyLıus ErıcHsen’s sledge 
party which perished, and the determination of longitude by transport 
of the watch thus came to rest, practically speaking, exclusively on 
chronometer 57203 in connection with watch K, both of which were 
carried by me. The importance of the watch comparisons, therefore, 
in the main only consists in the fact, that each of the sledge parties, 
according as they parted from the rest, were provided with a watch, 
the rate of which in the course of a month’s travelling might be 
supposed to have become settled under daily control according to 
the particular travelling conditions. It must, however, be supposed 
that the rate of the watches on the sledge trip differed from the one 
at home in the station at Danmarks Havn. The value of the rate 
was, therefore, unknown from the very start; it became the aflair 
of the individual cartographers to determine it in the course of the 
sledge trip or at the latest on the return to Danmarks Havn. 
During the journey in a northerly direction, when the sky was 
constantly clear, I had practically speaking taken determinations of 
19* 
