Survey of Northeast Greenland. 233 
greatest difference between two values of the same side is here 11m 
i. e. about sn of the length of the side. Station XXIII being deter- 
mined by X, XV and XXII, the uncertainty of XXII comes to in- 
fluence the position of Station XXIII, and thus again the position of 
Haystack. As the triangles through which Station XXIII is deter- 
mined have a particularly favourable shape, the uncertainty of XXII 
hardly plays any great part. 
Station XXIV is very favourably determined by VI, УШ and XV; 
the uncertainty of this station must be trifling. Besides the station 
is to a certain extent controlled by means of a determination of 
azimuth (see “The geogr. survey of Dove Bugt”). 
With the exeption of the stations XIX and XXI, which, as 
mentioned above, are of no importance as regards the connection 
wtth Haystack, one may take it for granted that the error of the 
position of the stations in Dove Bugt, in relation to the Observatory 
at Danmarks Havn, does not exceed a few metres. 
Geographical co-ordinates of the triangulation stations. 
According to the hypothesis advanced in 1912 by Dr. ALFRED 
WEGENER as to the movement of continents, Greenland was presumed 
to slide in a westerly direction. WEGENER makes an attempt to 
compule the average yearly movement for a period of 50,000 to 
100,000 years, and thus arrives at a yearly rate of 14—28 m. This 
hypothesis, so extremely far-reaching in its consequences, has lent a 
certain interest to the work of the Danmark-Ekspedition in the 
direction of determinations of longitude and triangulation, in that it 
has become possible, through the triangulation, to compare the 
results of the determination of longitude of the Germaniaexpedition 
in 1869—70 with that of the Danmark-Ekspedition in 1907. 
The determination of the geographical co-ordinates of the Ob- 
servatory at Danmarks Havn are mentioned in detail in the section 
“The Work in the Observatory”. The result of the determination 
became: 
ф = 76°46'14'.6 + 0”.4. 
[ = 1515™505.3 + 25.4 — 18°42'34” + 36” west of Grw. 
Azimuth of Cairn У from the Observatory A,—y = 858°17'40”.5. 
The computation of the differences of latitude and longitude in 
a network of triangulation is a problem treated in every geodetic 
compendium. The formule which have been used in the computation 
are the following: 
