GLACIERS 307 
corresponding to a particular temperature, humidity, change of 
temperature, and change of humidity. Every slight lowering of 
temperature deposits its appropriate form and quantity of ice 
crystals on every object exposed to these conditions. 
Thus on ice ponds or other masses of ice, at times the crystals 
are so deposited as to outline the form of the massive crystals in 
the ice—at times so as to show the orientation of the crystals on 
the surface. 
Probably the most beautiful form of crystal, and certainly 
the most distinctive one, was to be found in huge masses in all 
crevasses. Single crystals measured up to 2 inches across, and 
were built in the form of hollow pyramids. 
GLACIERS 
It is however when in the form of glaciers that one appreci- 
ates to the full the power of ‘the mighty molecule’: huge val- 
leys, 5, 10, 20, 30, even 50 miles wide, filled with moving ice, 
cut by this ice from the solid rock to a depth of thousands of feet; 
—huge streams of ice moving by virtue of their own enormous 
weight at a rate of 30 feet a year even in the most dormant 
glaciers. 
Hundreds of glaciers representing every type are to be found 
along the stretch of shore from Cape Adare to the Beardmore 
Glacier; some, like the Ferrar and Beardmore glaciers, accom- 
modating the outflow from the great ice plateau g000 to 11,000 
feet high, others fowing from local névé fields, and others little 
more than consolidated snow-drifts. 
Owing to the fact that the ‘ snow-line’ is at sea level, a very 
large proportion of the glaciers terminate in the sea and dis- 
charge bergs from their seaward faces as do many Greenland 
glaciers. More than this, however, the Antarctic glaciers, in- 
stead of coming to an end where. they rest on the sea bottom, 
often preserve their entities as glaciers or streams of ice while 
projecting many miles into the open sea. Examples of this type 
are furnished by ‘Glacier Tongue’ between Winter Quarters 
and Hut Point, and by the Nordenskidld and Drygalski ice 
tongues farther north. This latter pushes its way into the 
sea a distance of about thirty miles and has a volume, on a rough 
calculation, of fifty thousand million cubic yards. 
