Survey of Northeast Greenland. 417 
Throughout the winter and spring a partial re-crystallization of 
the deposited snow takes place. As the air contained in the snow 
must be saturated with ice vapour, the re-crystallization must take 
place, for the simple reason that the equilibrium pressure of vapour 
is different in the case of large and small crystals (the large ones 
“devour” the small), but apart from that the current of heat which 
from the warm ice must pass through the cold snow, serves to 
further the re-crystallization. The layer of snow nearest the ice eva- 
porates and condenses once more in the higher lying strata. In this 
Fig. 102. Lee belt at Mallemukfjældet, Holms Land. 
Accumulation of snow. Fog. June. 
manner, simultaneously with the transformation of the snow into 
névés, extensive, low cavities appear, principally between the ice 
and the snow. When these cavities collapse, in consequence of the 
weight of the snow deposited above them, the air is pressed through 
the snow with a peculiar, sighing sound, which phenomenon has been 
described by the word “sigh” (a “sigh” in the snow, the snow “sighs”). 
In the month of April the fall of snow is particularly small. 
The time of the spring blizzards is gone; the snow hardly drifts, 
and so the deposits of snow have ceased to increase. As early as 
the month of May the sun becomes so powerful that the snow may 
begin to melt, but not till the month of June does the melting begin 
in real earnest. The melting water from the upper layer of snow is 
absorbed by the lower-lying ones, which are gradually transformed 
into a complete slush of snow and water. The upper layers, which 
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