THE HEART OF THE ANTARCTIC 



known in South Victoria Land. Many varieties of snow 

 were observed. When precipitation occurred near freez- 

 ing-point the snow fell as large six-rayed feathery flakes. 

 It appeared that even at the same temperature, if the 

 chilling of the vapour-laden air was more rapid, the snow 

 fell as tiny felted spheres, one-tenth of an inch and more 

 in diameter. This we referred to as sago, or tapioca snow, 

 according to the coarseness of the grain. Snow falling in 

 colder conditions, appears as tiny compact six-rayed 

 crystals. At times when low temperatures prevailed, the 

 air was filled with tiny crystals of ice about one-hundredth 

 of an inch in diameter descending from a cloudless sky. 



Recently fallen snow is quite soft, but soon compacts 

 itself. This may take place in summer-time within a few 

 hours should a cold period succeed a warmer one. A 

 piecrust-like surface is produced in this way where a super- 

 ficial hardening of the soft snow has preceded, though 

 not sufficiently strong to support a heavily laden sledge. 

 Very soon, however, the snow becomes more firmly bound 

 together, and the usual smooth-sledging type of winter 

 snow-ice surface is produced. What is known as barrier 

 ice in the Ajitarctic is an immensely thick formation of 

 this compacted snow horizontally stratified. This is what 

 one sees in the face of the Ross Barrier and numerous 

 other small barriers along the coast. Its characteristic 

 horizontal surface, vertical fractures, and dazzling white- 

 ness distinguish it from other varieties of ice even at a 

 great distance. Nearer at hand, the stratification lines, 

 appearing every few inches apart, are readily noticeable. 

 Such barrier ice is really a snow-field afloat and may be 

 expected in tongue-like forms jutting out into the sea 

 at the debouchure of glaciers, or forming the clifl's along 

 the sea-fronts of piedmont glacier-slopes. The granules 

 increase in size and are more intimately interlocked in the 



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