Survey of Northeast Greenland. 445 
about 4 metres. According as the winter progressed, we had to break 
the ice in greater and greater depths in order to get water. When 
the ice attained a thickness of two to two and a half metres, the 
work of breaking it became so difficult that we gave it up, and in- 
stead of that we melted ice in order to get water. As far as I 
remember, that was in the month of January. From this it might 
seem, as if a depth of three metres is the approximate limit within 
which the lakes freeze to the bottom. It must then be supposed 
that a very large number of the small lakes in the course of the 
winter freeze to the bottom, to which state of affairs the organic 
life in them must consequently be adapted. 
The larger lakes and water courses. In Germania Land 
there are two very considerable lakes: Sælsøen, which is 1 to 3 km 
broad and about 50km long, and Annekssøen, about 1km broad 
and about 40 km long. Sælsøen is one of the largest lakes in Green- 
land. Both lie concealed in deep longitudinal valleys, of the nature 
of crevasses, with steep banks on both sides, which valleys, both of 
them have made foundations for considerable glaciers, coming from 
the inland ice. | 
The name of Sælsøen originates from the circumstance that on 
one occasion we thought we saw a seal in the lake. This was how- 
ever a mistake. 
The surface of the lake is only 4 to 5 m above the level of the 
sea. The water level varies somewhat, in that during summer time 
it may rise, presumably about one metre or possibly more, in conse- 
quence of the melting of the snow. When travelling on the lake in 
the spring, one encounters along the banks, up on the land, frag- 
ments of ice, which have drifted up there during the higher water 
level of the preceding summer. When in the beginning of August 
1912 I visited Sælsøen, the water level was about one metre higher 
than in May—June 1908. The rise of the water level must contribute 
materially to breaking the ice away from the land and so also to 
dissolving it. It is a likely supposition that, as a general rule, the 
lake becomes ice-free every year; in the unfavorable summer of 1907, 
however, the ice did not vanish entirely. 
In May 1908 TROLLE took a depth of water of 116m in the 
centre of Sælsøen!). On the same occasion it turned out that the 
water at a depth of 60 m became salt, almost like the water in Dove 
Bugt, though with a somewhat smaller degree of salinity. TROLLE is 
of opinion that this salt water cannot date from the time, when Sæl- 
1) Hydrographical Observations ete., р. 337. 
