Survey of Northeast Greenland. 309 
Horizontal base. 
However great the importance of the use of the vertical base 
may be in the geographical survey, it is, however, sharply limited 
by reason of the fact that it is only suitable for determining the 
border line between land and water. Besides it is a necessary 
condition of the measuring of distances by depression angles that 
one is able to ascend a mountain, which is not always possible. 
Therefore, not only during the inland voyages, but also now and 
then. during the coast survey it becomes necessary to use the hori- 
zontal base. 
On sledge journeys the expedition made use of a measuring tape 
for the direct measuring of horizontal distances. On a few occasions, 
where the measuring tape could not be used, either on account of 
the nature of the terrain, or because the labour would have been 
insuperable, we made use of Souchier's distance meter (see p. 259). 
Our measuring tape was a small steel tape, 5 metres long and 
provided with a leather case; it could be carried conveniently in a 
pocket. Throughout the whole of its length it was divided into 
centimetres, and besides the first decimetre was divided into milli- 
metres. We did not use plugs or the like. In order to use the 
measuring tape level, fairly firm ground was requisite, preferably a 
solid snow-field or ice bare of snow. Before measuring we paced 
the base and marked its termini with tent poles. During the mea- 
suring the man in front marked off the end of every length of the 
tape by making a notch with a knife in the snow or ice, and at the 
same time he wrote the number of the tape length in the snow, 
alongside the notch, and called out the number so loudly that the 
man walking behind could hear it, and thus check it. A precaution 
of this kind is necessary, as otherwise there will almost invariably 
arise a doubt as to the number of the tape lengths. An advantage 
gained by this precaution was that we were only obliged to measure 
the bases once throughout their entire length. 
The length of the directly measured bases rarely exceeded sixty 
tape lengths, or 360 m, which was, as a rule, sufficient when it was 
simply a question of measuring the altitude and mutual position of 
a few neighbouring points. Very often, however, we extended our 
base line into a base triangle by means of a small triangulation, 
either because the terrain was unfavourable for measuring a suffi- 
ciently long base in the direction desired, or because the establishing 
of the various points in the terrain necessitated a third position of 
the instrument. 
Ås an example I shall quote the measuring from Station III on 
