Survey of Northeast Greenland. 301 
In the rarely occuring cases where — for instance on the Ger- 
maniaexpedition as well as on the Danmark-Ekspedition — in a 
smaller field of operations a complete triangulation has been under- 
taken, in connection with a carefully performed trigonometrical level- 
ling of the stations, the error in the altitude of the stations above 
the mean sea level will only quite exceptionally amount to 2 m, and 
yet an uncertainty of 2m is even here a low estimate, as soon as 
it comes to using the altitude of the station as the basis of a coast 
survey. This is partly due to the tidal movement and partly to the 
fact that tidal pressure ridges and ice foot may produce an “apparent’ 
coast line, which may be several metres higher than the “true” coast 
line. So at Germania Harbour, where the Germaniaexpedition wintered, 
I have found an ice foot, the altitude of which above the mean sea 
level was about 3m. 
On sledge trips the trigonometric levelling of the stations is, 
however, extremely often either quite out of the question or of such 
a primitive kind that it may only seem to control a barometric 
levelling, which according to the circumstances may be encumbered 
with a very considerable error, for instance of 20 to 30 metres. 
It is, however, self-evident that the accuracy of the distance 
measuring is dependent upon the altitude of the station and is 
greatest in the most highly situated stations, because here the relative 
error of altitude, is generally smallest. Also in this respect the 
H’ 
example given by BORGEN and CoPELAND from Kap Bremen is not 
quite so good as it might be, as an altitude of 1000 m is very rarely 
met with in stations situated on coast mountains. At all the ob- 
servation stations of the Danmark-Ekspedition, amounting to nearly 
200, this altitude was never reached, even though a couple of times 
we came very near to it. So also in my survey of the region round 
Scoresby Sound in 1900 my stations never reached an altitude of 
1000 m. 
But though one is thus forced to acknowledge that the mea- 
suring of distances with the altitude of the station as its basis is, 
in manifold instances, encumbered with great uncertainty, the method 
has, however, its indisputable advantages, so that one never ought 
to omit using it in geographical surveys, where it is possibe to use 
it, even in the case of very small altitudes of stations, for instance 
of 50m. This is among other things due to the fact that in an 
intricate terrain, for instance within the skerries of Jokelbugten (the 
glacier bay) and in Dove Bugt it is impossible to get a general view 
of things without ascending some mountain. If the terrain is low, 
even quite a small altitude is of importance, but having ascended 
the mountain one gets the vertical base and the measuring of the 
