302 I. P. Kocu. 
distance for next to nothing, because the barometric measurement 
and that of the angles of depression only. require a minimum of 
time. It is true that the measuring of the distance, when the alti- 
tude is inconsiderable, becomes most uncertain, but one knows it 
and can pay sufficient attention to it, not only while drawing the 
map, but also on the journey itself, in that one looks for the necessary 
control through a convenient choice of the following station. A 
control of this kind will, however, only include a few of the points 
measured at; but one may then, while drawing the map, by examining 
the distance to the points controlled form an estimate of the error 
of the distance to the uncontrolled points, computed through the 
angles of depression. 
Particularly at low-lying stations one may run the risk of the 
coast line, in remote localities, falling under the horizon, though one 
may not be able to perceive it immediately. If only for this reason, 
it will in any case be most prudent to level at the horizon. 
The dip of the sea horizon thus constitutes a minimum of the 
values which the angles of depression from the station in question 
may assume; when one gets near it, the measuring of the distances 
becomes quite unreliable. (As to the determination of the dip of the 
sea horizon see рр. 807—308). 
In the Jökelbugten, where the highest station was situated at 
330 m, whereas the greater part were considerably lower, the method 
in itself was not very satisfactory; but the travelling conditions in 
this place did not at all permit of the time-wasting and difficult 
measuring of the horizontal base. If we had not used distance 
measuring with a vertical base, we should have been reduced to 
determine the mutual position of the islands only by means of 
bearings from the various stations, and it would then have been 
simply impossible to make head or tail of the complex material, 
because in numerous cases it only became possible, through the 
measuring of the distance, to establish what sights were directed 
from the different stations at the same islands and skerries. 
At the measuring of the altitude of stations, one is, as a rule, 
forced to have recourse to barometric measuring with aneroids, be- 
cause this method, with a minimum of work, leads to a result which 
offers a satisfactory guarantee against gross errors. The principles 
of barometric measuring are, besides in other places, set forth in 
H. Moun, Praktisk vejledning til hejdemaaling med barometer, Kri- 
stiania 1888. The tables to be found in this little book have been 
used at the computations of the barometric measurings of the 
expedition. 
A more accurate barometric levelling demands simultaneous 
