ife of a waterspout
appears to be brief. They rarely endure for more than a few minutes,
or journey over the sea for more than two or three miles before the
column appears to be broken by some swaying of the atmosphere. As
these peculiar storms are likely to damage ships, the old-fashioned
sailors were accustomed to fire at them with cannon. It has been
claimed that a shot would break the tube and end the little
convulsion. This, in view of the fact that they appear to be easily
broken up by relatively trifling air currents, may readily be
believed. The danger which these disturbances bring to ships is
probably not very serious.

The special atmospheric conditions which bring about the formation of
waterspouts are not well known; they doubtless include, however, warm,
moist air next the surface of the sea and cold air above. Just why
these storms never attain greater size or endurance is not yet known.
These disturbances have been seen for centuries, but as yet they have
not been, in the scientific sense, observed. Their picturesqueness
attracts all beholders; it is interesting to note the fact that
perhaps the earliest description of their phenomena--one which takes
account in the scientific spirit of all the features which they
present--was written by the poet Camoens in the Lusiad, in which he
strangely mingles fancy and observation in his account of the great
voyage of Vasco da Gama. The poet even notes that the water which
falls when the spout is broken is not salt, but fresh--a point which
clearly proves that not much of the water which the tube contains is
derived from the sea. It is, in fact, watery vapour drawn from the air
next the surface of the ocean, and condensed in its ascent through the
tube. In this and other descriptions of Nature Camoens shows more of
the scientific spirit than any other poet of his time. He was in this
regard the first of modern writers to combine a spiritual admiration
for Nature with some sense of its scientific meaning.

In treating of the atmosphere, meteorologists base their studies
largely on changes in the weight of that medium, which they determine
by barometric observations. In fact, the science of the air had its
beginning in Pascal's admirable observation on the changes in the
height of a column of mercury contained in a bent tube as he ascended
the volcanic peak known as Puy de Dome, in central France. As before
noted, it is to the disturbances in the weight of the air,