exposed to the air. As the temperature rises the change becomes more
rapid. The steam-making of the arts is merely that of all nature,
hastened artificially and intentionally.

The element of pressure, mentioned above, enters into the proposition
because water boils at a lower temperature, with less heat, when the
weight of the atmosphere is less than normal, as it is at great
elevations, and on days when, as we now express it, there is a low
barometer. Long before any cook could explain the fact it was known that
the water boiling quickly was a sign of storm. It has often been found
by camping-parties on mountains that in an attempt to boil potatoes in a
pot the water would all "boil away," and leave the vegetables uncooked.
The heat required to evaporate it at the elevation was less than that
required to cook in boiling water. It is one of the instances where the
problems of nature intrude themselves prominently into the affairs of
common life without previous notice.

This universal evaporation, under varying circumstances, is probably the
most important agency in nature, and the most continuous and potent.
There was only so much water to begin with. There will never be any less
or any more. The saltness of the sea never varies, because the loss by
evaporation and the new supply through condensation of the
steam--rain--necessarily remain balanced by law forever. The surface of
our world is water in the proportion of three to one. The extent of
nature's steam-making, silent, and mostly invisible, is immeasurable and
remains an undetermined quantity. The three forms of water combine and
work together as though through intentional partnership, and have, thus
combined, already changed the entire land surface of the world from what
it was to what it is, and working ceaselessly through endless cycles
will change it yet more. The exhalations that are steam become the water