Survey of Northeast Greenland. 221 
certainty with which the sides of the triangulation network are deter- 
mined at less than en of the length of the sides. This corresponds 
well with the uncertainty of the base measured, in that the computed 
mean error 0.14 m is very nearly sae of the base. It thus seems as 
if there has been a substantial harmony between the means used at 
the base line measurement and triangulation. 
As far as the practical application of the triangulation net was 
concerned, the uncertainty with which it was encumbered was of no 
importance whatever. 
The Cairns VI, M and XIII. 
The position of Cairn VI was computed through: 
Triangle V—VI—VIII Triangle VI— VIII— XII 
У 78941'38” VIII 106°29'07” + 03” 
УШ 65 2041 XII 43 4747 +00 
N Sb" VI 29°43'03” 
The double computation of the side УГ-УШ gave log VI— VIII 
__ 1 4.29124 
~~ | 4.29124 ° 
The position of Cairn М was computed through: 
Triangle V—VII—M Triangle V—XII—M 
У 66°56’11” - 02” У 32918'30” + 01” 
VII 31 3207 +02 XII 30 1915 —01 
М 81931'40” 117°22'15” 
The double computation of the side XII—M gave log XII—M 
Г 3.12255 
— À 3.72262" 
The position of Point XIII. At a rather advanced stage of 
the triangulation process itself I determined to include Point XIII in 
our observations, because I estimated that this point which lay near 
the outer coast might be of some importance, among other things 
in the case of a possible continuation of the triangulation net in a 
northern direction along the coast. No cairn had been built in this 
place, but as Point XIII was a hill of a rather regular domelike 
shape, I hoped to be able to determine the position rather accurately, 
even though there was no cairn. As we only succeeded in getting 
two sights at the point, the control of measurements could only be 
achieved through the levellings, but the computation of the latter 
showed with sufficient clearness that the measurement at this point 
had failed so completely that there was only one possible explanation 
