f the submersible to be certain of its destruction. To
accomplish this, it would seem that the ideal combination would be the
control of an explosive carrier by radio energy directly from an
aeroplane. Thus we would have a large explosive charge under water
where it can most effectively injure the submersible, controlled by
the guidance of an observer in the position best suited to watch the
movements of the submerged target.

The third method by which to frustrate the attack of the submersible
is to give better protection to the merchant marine itself. While a
great deal of ingenuity is being concentrated on the problem of
thwarting the submersible, but little common sense has been used.
While endeavoring to devise intricate and ingenious mechanisms to sink
the submersible, we overlook the simplest safeguards for our merchant
vessels. To-day, the construction of the average ship is designed to
conform to the insurance requirements. This does not mean in any way
that the ship is so constructed as to be truly safe. Thousands of
vessels that are plying the seas to-day are equipped with bulkheads
that are absolutely useless because they do not extend high enough to
prevent the water from running from one part of the ship to another
when the ship is partially submerged. Then again, the pumping system
is so arranged as to reach the water in the lower part of the hull
when the ship is up by the head. Should the ship be injured in the
forward part and sink by the head, these pumps would be unable to
reach the incoming water before her condition had become desperate.
There is a vessel operating from New York to-day worth approximately a
million dollars, and if she were equipped with suitable pumps, which
would cost about a thousand dollars, her safety would be increased
about forty per cent. Her owners, however, prefer running the risk of
losing her to expending a thousand dollars! If the merchant vessels
were made more torpedo-proof, it would be an important discouragement
to the U-boat commander. During the past two years of the war,
nineteen battleships have been torpedoed, and out of this number only
three have been sunk, showing that it is possible by proper
construction to improve the hull of a ship to such an extent that it
is almost torpedo-proof. While it may not be practicable, on account
of the cost, to build merchant vessels along the lines of armed ships,
nevertheless much could be done to improve their structural