Hydrographical Observations from the Danmark Expedition. 399 



The great differences in the thickness of ice, found on quite ad- 

 jacent stations, show that the underside of the ice must bave been 

 very uneven. 



The thickness of snow was very irregular and dependent on local 

 conditions. As the direction of the %\and, when the snow fell, was 

 mainly N. W., the snow was heaped up as a rule on the west side of 

 the islands. At such places the ice was pressed doAvn by the Aveight 

 of the masses of snow and sea-water flowed up over the ice through 

 cracks and thus formed a layer of snow-mush, which might be over 

 1 m. in depth. 



In the spring of 1908 ice on the fjords was everywhere granular 

 snow-ice with single layers of hard sea-ice and at several places there 

 were veins of salt-water among the ice layers (a sample from one of 

 these had a salinity of 65.4 p. m.). 



The melting of this ice proceeded more rapidly, just as in Dan- 

 marks Havn, than the ice of the previous year which had been through- 

 out distinctly sea-ice (i. e. frozen sea-water). 



On July 18th 1908 already the ice had broken up everywhere 

 in the fjords, thus at a time when the ice in 1907 still had an average 

 thickness of l%m. In 1907 the ice in Øresund broke up first on 

 August 13th and in Dovebugt it did not break up at all. 



The ice on the freshwater lakes, in contrast to the sea-ice, was 

 extremely hard and of a different darker colour. 



Observations on the thawing of the fjord-ice in Øresund in 1908. 



(Table 8 p. 400). 



Remarks: On June 18th 1908 the winter-ice still lay quite un- 

 broken everywhere in Øresund and the pack-ice out to sea lay im- 

 movable, frozen solidly to the outer fringe of rocks and islands. Above 

 the fjord-ice was a layer of "mush" (mixed snow and water) wth a 

 temperature of — 2° C, whilst the snow temperature varied in the 

 course of the day between + 0.1 and -f- 0.3. Thus, the snow and 

 strongly saline mush were about to melt. On the under side of the 

 fast ice there was a layer of water ca. 25 m. thick which was cooled 

 down to freezing point ( — 1.76°) (Series LX A). 



The fjord-ice was much thinner than in the previous year at the 

 same time (ca. % m. against l%m.) and of a different structure. 

 (In 1907 the ice was hard and solid, in 1908 soft and porous). 



Further, there was more snow on the ice than in 1907 and the 

 melting of the snow seemed scarcely so far advanced as in the year 

 previously. The temperature of the air and surface-water was nearly 

 the same in the two years. 



From the 24th to 26th June the fjord-ice decreased greatly in 

 thickness, following on a warm wind (temperature about -f 6° and 



