248 THE ANTARCTIC. 



summer, so low that they hardly anywhere suffice to 

 melt the snow, whilst in the boundless open ocean the 

 formation of an uninterrupted sheet of ice is prevented 

 by its perpetual violent agitation ; and this is so all the 

 more, because the occasional nuclei for ice formations 

 in the shape of scattered larger island groups in those 

 distant southern seas are absent ; hence again the pre- 

 ponderance of icebergs, and the relative insignificance 

 of sea ice. 



Land ice or glacier ice is admittedly in its origin 

 snow in a changed form. In our temperate zones, in the 

 Alps for example, the dry powdery snow, falling at a 

 high elevation, is swept by the wind into lower valleys, 

 where it collects in wide hollows — the birthplaces of 

 odaciers. Here the snow masses accumulate and reach 

 down to a certain height, called the Snow Line, below 

 which the temperature of the air is sufficient to liquefy 

 the snow. 1 The thaw of the summer day, succeeded by 

 the frosts of night, causes the ice to assume a granulated 

 shape, and gives it the peculiar character indicated by 

 the terms " Firn-snow " and " Firn-ice ". 2 Finally, under 

 the pressure of the snow masses heaped up in the course 

 of years, glacial ice is formed, which flows down at 

 varying rates. 



These phenomena do not present themselves in the 

 south polar districts, or, to speak more correctly, they 



1 This definition of the Snow Line is sufficient for the purpose in 

 hand ; for a fuller and more accurate definition, see Tyndall on The 

 Forms of Water. — The Translator. 



2 The cognate word of "fern" is "far". Hence "Firnewein" 

 means "far wine," old wine, wine of a distant or old vintage; similarly 

 " Firnschnee," and " Firneis" mean snow and ice distant both in space 

 (being found at a high elevation), and in time (being the accumulated 

 snow and ice of many winters). We have no corresponding term in 

 English ; possibly the words of our text may prove acceptable. — The 

 Translator. 



