perienced by the crews of earlier boats have
been removed. This perfection of technical details which was thus
gradually approached also permitted a very considerable increase in
the fighting power of submarine boats. The number of torpedo tubes
was increased and it became possible to carry a larger reserve stock
of torpedoes. Submarines of to-day furthermore carry guns varying in
calibre, attaining in some instances four inches, and when in later
years it became evident that one of the most dangerous enemies of
the submarine was the airplane, some of the boats were equipped even
with anti-aircraft guns.

[Illustration: Copyright by Munn & Co., Inc. From the _Scientific
American_.

_Modern German Airplane Types._]

In the United States Navy the submarine has never been popular.
Indeed it is by no means certain that in comparison with other
navies of the world the United States was not better off in
underwater boats in 1911 than she was three years later when the
warcloud broke. The bulk of our naval opinion has always been for
the dreadnoughts. A change of political administration at Washington
in 1912 gave a temporary setback to naval development, and the
submarines, being still a matter of controversy, languished. Few
were built and of those few many showed such structural weakness
that the reports of their manoeuvres were either suppressed, or
issued in terms of such broad generality that the public could by no
possibility suspect, what all the Navy knew to be the fact, that the
submarine flotilla of the United States was weak to the point of
impotence.

Happily we had nearly three years in which to observe the progress
of the war before becoming ourselves embroiled in it. During this
period our submarine fleet was somewhat increased, and upon our
actual entrance upon the struggle a feverish race was begun to put
us on an equality with other nations in underwater boats. It would
have been too late had any emergency arisen. But Germany had no
ships afloat to be attacked by our submarines had we possessed them.
Her own warfare upon our merchant shipping could not be met in kind,
for submarines cannot fight submarines. We have, therefore, up to
the present time, not suffered from the perilous neglect with which
we long treated this form of naval weapon.

Indeed the submarine fleet of the United States Navy at the
beginning of the war was so inconsiderable that foreign writers on
the subject ignored it. In 1900 w