The water spout produced by the explosion sometimes completely covers
the torpedo boat, and the latter would be sunk by it were not
all apertures closed so as to make her a true buoy. What appears
extraordinary is that the explosion does not prove as dangerous to the
assailant as to the adversary. To understand this it must be remembered
that, although the material with which the cartridges are filled is of
an extreme _shattering_ nature, and makes a breach in the most resistant
armor plate, when in _contact_ with it, yet, at a distance of a few
meters, no other effect is felt from it than the disturbance caused by
the water. This is why a space of 12 meters, represented by the length
of the torpedo spar, is sufficient to protect the torpedo boat. The
attack of an ironclad, however, under the conditions that we have just
described, is, nevertheless, a perilous operation, and one that requires
men of coolness, courage, and great experience.

[Illustration: ATTACK BY A TORPEDO BOAT UPON AN IRON CLAD SHIP OF WAR.]

There is another system which is likewise in use in the French navy, and
that is the Whitehead torpedo. This consists of a metallic cylinder,
tapering at each end, and containing not only a charge of gun cotton,
but a compressed air engine which actuates two helices. It is, in fact,
a small submarine vessel, which moves of itself in the direction toward
which it has been launched, and at a depth that has been regulated
beforehand by a special apparatus which is a secret with the inventor.
The torpedo is placed in a tube situated in the fore part of the torpedo
boat, and whence it is driven out by means of compressed air. Once
fired, it makes its way under the surface to the spot where the shock of
its point is to bring about an explosion, and the torpedo boat is thus
enabled to operate at a distance and avoid the dangers of an immediate