The pressure of
the wire will then melt the ice and allow the wire to sink down
through the ice as shown in Fig. 2. The wire will continue to cut
its way through the ice until it passes all the way through the
piece, as shown in Fig. 3. This experiment not only illustrates
how ice melts under pressure, but also how it solidifies when the
pressure is removed, for the block will still be left in one piece
after the wire has passed through.
Another peculiar property of ice is its tendency to flow. It may
seem strange that ice should flow like water, but the glaciers of
Switzerland and other countries are literally rivers of ice. The
snow which accumulates on the mountains in vast quantities is
turned to ice as a result of the enormous pressure caused by its
own weight, and flows through the natural channels it has made in
the rock until it reaches the valley below. In flowing through
these channels it frequently passes around bends, and when two
branches come together the bodies of ice unite the same as water
would under the same conditions. The rate of flow is often very
slow; sometimes only one or two feet a day, but, no matter how
slow the motion may be, the large body of ice has to bend in
moving.
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