TRANSACTIONS OF SUCTION C. 575 



Tt has a striking resemblance to the undisturbed surface of a frozen ocean, the lonjj 

 but not high billows of which rolling from east to west are not easily distinguishable 

 to the eye. 



The principal factor which makes this surface so remarkably even is the wind. 

 The levelling influence of the wind may easily be studied in our Norwegian moun- 

 tains in the winter ; there it may be seen how its prevailing effect is to remove every 

 prominence, the snow being carried from the mountains into the valleys to fill them 

 and make the mountains disappear. This has of course also been the case in 

 Greenland, only to a much higher degree, when its present glacial period com- 

 menced. The snow grew annually, gradually the valleys were filled up, the 

 mountains disappeared, and the snow-field was produced which we now see. 



The surface of the snow-field in the interior consists of soft, loose, and dry snow, 

 which is easily moved by the wind. Even in midsummer there is no snow-melting 

 of importance in this interior. Even with the six-feet sticks we use for «Z;(-runmng 

 I could not reach hard ice or snow underneath the soft layer. At intervals of six 

 to ten inches quite thin ice-crusts occurred ; between them there was, however, 

 soft snow like that of the surface. These thin ice-crusts are evidently formed bv 

 the direct influence of the sun during midsummer. The sun is then, in the middle 

 of the day,_able to melt the surface of the snow a little; in the night, however, it 

 freezes again. Whether these ice-crusts at certain intervals indicated annual 

 layers of snow, or whether they only indicated heavy snowfalls during the summer, 

 I am not able to decide. I am, however, inclined to the latter opinion — at all 

 events, to some extent. 



We had snow fall almost every day. When we compare this with the fact just 

 stated, that there is no real snow-melting in the interior, it would seem as if we 

 were obliged to conclude that the quantity of snow is still increasing in the interior 

 of Greenland. This cannot, however, easily be the case— at all events, not in any 

 considerable degree ; for if it were so, the quantity of ice and snow must also increase 

 towards the coasts. 



Judging from the observations and measurements which during several years 

 have been made on the west coasts of Greenland, it seems, however, as if the ice 

 varies a little from one year to another, but that upon the whole its quantity keeps 

 very nearly on the same level. We are not thus entitled to assume that the quantity 

 of snow is increasing in the interior. 



But what is the reason why it does not increase ? As already mentioned, the 

 snow-melting cannot be of any importance. The evaporation from the snow-surface 

 cannot, in my opinion, be of much more importance, as it must be quite a trifle 

 with such a low temperature of the air, and where on most days a little .snow falls. 

 _A factor of more importance is, I think, the snowdrifts occasioned by the wind, 

 which most likely has a tendency to blow from the cold and high interior towards 

 the lower and warmer coasts. In the middle of the continent the winds blow, 

 however, in all possible directions, and thus, I think, even this factor is of no great 

 importance. The principal factor to keep the level must, in my opinion, be the 



Eressure which is produced within this immense layer of ice and snow. On one 

 and this pressure forces the ice downwards along the sloping sides of the moun- 

 tains, through the valleys and towards the sea, into which it falls in form of ice- 

 streams or glaciers, and is carried away in form of icebergs or is melted. 



To a great many peoople it does not seem necessary that the ice must force its 

 way to the coast in this manner, but I think that if we said that the interior of 

 Greenland was filled or covered by an immense layer of pitch nobody would doubt 

 that this would find its way to the sea; but there is really in that respect no great 

 difl'erence between these two materials ; by the immense pressure the ice is pro- 

 bably made even more fluid than melting pitch. 



But the pressure brings the ice to the sea not only in the form of ice, but also 

 (and certainly in larger quantity) in the form of water. As is generally known, 

 ice has the peculiarity that by pressure it can be transformed into water at tem- 

 peratures lower than its common melting-point ; in other words, pressure lowers 

 the melting point of the ice. I do not think, however, that it is principally in this 

 manner the pressure contributes to the melting of the snow, as such a high pressure. 



