iron coffin, and that when a
shell had made its way through one side of his ship he didn't want
any obstacle presented to impede its passing out of the other side.

[Illustration: (C) U. & U.

_Launching a Hydroaeroplane._]

The all important and even vital necessity for speed also detracted
much from the value of aircraft in offensive operations. It was
found early that you could not mount on a flying machine guns of
sufficient calibre to be of material use in attacking fortified
positions. If it was necessary for the planes to proceed any
material distance before reaching their objective, the weight of
the necessary fuel would preclude the carriage of heavy artillery.
In the case of seaplanes which might be carried on the deck of a
battleship to a point reasonably contiguous to the object to be
attacked, this difficulty was not so serious. This was demonstrated
to some extent by the British raids on the German naval bases of
Cuxhaven and Wilhelmshaven, but even in these instances it was bombs
dropped by aviators, not gunfire that injured the enemy's works. But
for the airplane proper this added weight was so positive a handicap
as to practically destroy its usefulness as an assailant of
fortified positions.

The heavier weapons of offence which could be carried by the
airplane even of the highest development were the bombs. These once
landed might cause the greatest destruction, but the difficulty of
depositing them directly upon a desired target was not to be
overcome. The dirigible balloon enjoyed a great advantage over the
airplane in this respect, for it was able to hover over the spot
which it desired to hit and to discharge its bombs in a direct
perpendicular line with enough initial velocity from a spring gun to
overcome largely any tendency to deviate from the perpendicular. But
an airplane cannot stop. When it stops it must descend. If it is
moving at the moderate speed of sixty miles an hour when it drops
its missile, the bomb itself will move forward at the rate of sixty
miles an hour until gravity has overcome the initial forward force.
Years before the war broke out, tests were held in Germany and
France of the ability of aviators to drop a missile upon a target
marked out upon the ground. One such test in France required the
dropping of bombs from a height of 2400 feet upon a target 170 feet
long by 40 broad--or about the dimensions of a small and rather
stubby ship. The results were uniformly dis