Report on the expedition. 15 
hold of a dragging trace, thus overthrowing the dogs which were then 
hauled underneath the sledge and sometimes hurt by being over- 
run by it. 
The new ice covered a considerable extent of water, and from Shan- 
non Island to Koldewey Island more than 60 % of the traversed ground 
was over thin ice, while from the south point of Koldewey Island to 
Danmark’s Havn, we did not in all pass 10 % of old ice. Those large sheets 
of new ice ranged in thickness from 50cm to an absolute minimum, 
and great care should be exercised in passing, as it would take far too 
long to ascertain the thickness all the way across a broad pond before 
taking the sledges over. We used to drive the sledges over the ice, judg- 
ing its thickness by the sound of our footsteps, and only when the ice 
sounded very thin, we stopped to investigate, taking good care only 
to leave the sledges standing in places where two or more layers of ice 
were pushed underneath each other, so as to make the stopping place 
as solid as possible. 
Salt-water ice is always very tough, and so it was possible to drive 
over ice, which bent under the sledges and in thickness did not exceed 
two inches, but care must be exercised and judgement used, as the tem- 
perature of the preceeding day makes great difference as regards its 
strength. Ice formed at a comparatively high temperature has con- 
siderably more flexibility than ice formed at a lower one. The former 
will bend very considerably before breaking, and may at the same time 
have softer spots of the same thickness, where the sledge cuts through. 
The ice formed at a low temperature is brittle and does not bend so 
easily, but still a sledge may be run over a short distance of this kind 
of ice without much danger — even if the ice in thickness does not 
exceed 5 cm. | 
The different kinds of ice may be distinguished through the sound 
of the footfall, which is muffled on ice formed at comparatively high 
temperatures, while ice frozen on a single night by a low degree of cold 
gives a ringing sound. 
On Sept. 29th we reached the first stretch of thin ice which proved 
impassable, and we were consequently forced to follow its edge towards 
the west, as we did not think it prudent to go further out to sea. Luckily 
we found a place where overlapping sheets of thin ice promised a com- 
paratively safe road, and in a little less than three hours we had passed 
this first lake. On the 30th we came to another lake, which was so 
broad that it took us 5 hours’ hard driving to pass it — often over ex- 
ceedingly thin ice. 
On Oct. Ist we were stopped by perfectly open water which — 
from an elevation of 3 metres — we saw reaching to and beyond the 
horizon, and as we did not know how long we might have to wait before 
being able to proceed, we thought it most prudent to take all the dog- 
feed, which Глов and OLSEN could spare, and send them back with 
