t its origin and during its progress, falls down three
precipices--the first fall is equivalent in energy to the descent of a
ton weight down a precipice 22,320 feet high-over four miles; the second
fall is equal to that of a ton down a precipice 2900 feet high, and the
third is equal to a fall of a ton down a precipice 433 feet high. I have
seen the wild stone avalanches of the Alps, which smoke and thunder down
the declivities with a vehemence almost sufficient to stun the observer.
I have also seen snowflakes descending so softly as not to hurt the
fragile spangles of which they are composed. Yet to produce from aqueous
vapor a quantity which a child could carry of that tender material
demands an exertion of energy competent to gather up the shattered
blocks of the largest stone avalanche I have ever seen and pitch them to
twice the height from which they fell."

When we contemplate the foregoing facts as related to so small an amount
of water as nine pounds, and multiply this result by the amount of snow-
and rainfall each year and the amount of ice that is congealed and again
liquefied by the power of the sun's rays, we are appalled, and shrink
from the task of attempting to reduce the amount of energy expended in a
single year to measurable units.

Having considered water in its relation to heat in the preceding
chapters, we will now take up the subject of water in its relation to
ice and snowfall and the phenomena exhibited in ice rivers, commonly
called glaciers.

When water is under pressure the freezing point is reduced several
degrees below 32 degrees Fahrenheit. This fact has been determined by
confining water in a close vessel and putting it under pressure and
subjecting it to a freezing mixture, and by this means determining the
freezing point under such conditions. By putting a bullet or something
of that nature into the water that is subjected to pressure one can tell
by shaking it when the freezing point is reached. If water is put under
pressure and cooled to a point below 32 degrees, and yet still remains
in the liquid state, it may be suddenly congealed by taking off the
pressure; this shows that the pressure helps to hold the molecules in
the position necessary for the liquid state, and prevents the
rearrangement of them that takes place at the moment of freezing. When
the water molecules are arranged for the liquid condition they may be
compared to a spring that is wound up and held in position b