Survey of Northeast Greenland. 369 
Finally the routes of BERTELSEN in March 1908 and Косн in 
May 1908 have been delineated, in as far as they went across the 
inland ice to Dronning Louises Land. 
On the map scale 1 : 500000 I have not been able to delineate 
the observation stations, because of their overwhelming number. As 
far as the two journeys on the inland ice are concerned, the stations 
are, however, discernible by means of the figures of altitudes, put 
in along the travelling routes. 
I have mentioned, on several occasions, how heterogenous the 
cartographic material of the Danmark-Ekspedition is — and neces- 
sarily must be — as regards completeness and reliability. For the 
tracts in the neighbourhood of the stations and the travelling routes 
the material often contains such a number of details that it has not 
been possible to include them in the map, whereas in the regions 
situated at the greatest distance from the observation stations there 
are only few and often uncertain data. This circumstance, as self- 
evident as it is unavoidable, has caused considerable difficulties in 
the preparation of the map. When making maps of regions so diffi- 
cult of access as Northeast Greenland, it is not justifiable to condemn 
all the less certain data, seeing that these, in the absence of others 
and better ones, are meanwhile of very considerable value; but on 
the other hand, the fact-that in this manner the map becomes in- 
complete and unreliable, as far as certain tracts are concerned, ought 
not to weaken confidence in those parts of the map which have 
been prepared on the basis of more reliable and complete material. 
This consideration has, among other things, been a contributory 
factor towards my delineating the above-mentioned travelling routes 
and observation stations, because in that manner one gets a very 
simple means of estimating, where one may rely on the maps and 
where one ought to evince a greater or less degree of precaution as 
to the information contained in the map. 
Below I shall give a few other points for the valuation of the 
reliability of the map. Here I must first of all insert a remark to 
the effect that the delineation of the travelling routes also has another 
object, that is to give an idea of who has performed the measurings, 
and where the persons in question have undertaken them. 
The information given in this respect by the travelling routes 
must necessarily be incomplete, for which reason I shall, in this 
place, give some supplementary notes, dealing with this question. 
HAGEN took part as an assistant in the triangulation work of 
1906, in the course of which he made surveys and drew a map of 
the area triangulated. The map was a good deal used during the 
stay of the expedition in Greenland, but only in the case of a few 
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