ndon the advantage which this
gives him, and to commit himself to such an element as the air, in
which the power required to lift himself and his goods would be
immeasurably greater than that needed to transport them from place to
place.

The amount of misdirected ingenuity that has been expended on these
two problems of submarine and aerial navigation during the nineteenth
century will offer one of the most curious and interesting studies to
the future historian of technological progress. Unfortunately that
faculty of the constructive imagination upon which inventive talent
depends may too frequently be indulged by its possessor without any
serious reference to the question of utility. Fancy paints a picture
in which the inventor appears disporting himself at unheard-of depths
below the surface of the sea or at extraordinary heights above the
level of the land, while his friends, his rivals, and all manner of
men and women besides, gaze with amazement! Patent agents are only too
well aware how often an inordinate desire for self-glorification goes
along with real inventive talent, and how many of the brotherhood of
inventors make light of the losses which may be inflicted upon
trusting investors so long as they themselves may get well talked
about.

Nations may at times be infected with this unpractical vainglory of
inventiveness; and on these occasions there is need of all the
restraining influence of the hard-headed business man to prevent the
waste of enormous sums of money. The idea that military ascendency in
the future is to be secured by the ability to fly through the air and
to dive for long distances under the water has taken possession of
certain sections in France, Germany, Russia, Great Britain and the
United States. Large numbers of voluble "Boulevardiers" in Paris have,
during the last years of the nineteenth century, made it an article of
their patriotic faith that the future success of the French navy
depends upon the submarine boat. The question as to what an enemy
would do with such a boat in actual warfare seems hardly ever to occur
to them; and, indeed, any one who should venture to put such a query
would run the risk of being set down as a traitor to his country!

More important to the student of the practical details of naval
preparation is the great question as to the point at which the contest
between shot and armour will be brought to a standstill. That it
cannot proceed indefinitely may be