and which would
be a distraction and a recreation to his disappointed mind.

CHAPTER XV. THE AUTOMATIC SHELL

In a large building, not far from the lens-house in which Roland Clewe
had pursued the experiments which had come to such a disappointing
conclusion, there was a piece of mechanism which interested its inventor
more than any other of his works, excepting of course the photic borer.

This was an enormous projectile, the peculiarity of which was that its
motive power was contained within itself, very much as a rocket contains
the explosives which send it upward. It differed, however, from the
rocket or any other similar projectile, and many of its features were
entirely original with Roland Clewe.

This extraordinary piece of mechanism, which was called the automatic
shell, was of cylindrical form, eighteen feet in length and four feet in
diameter. The forward end was conical and not solid, being formed of a
number of flat steel rings, decreasing in size as they approached the
point of the cone. When not in operation these rings did not touch one
another, but they could be forced together by pressure on the point
of the cone. This shell might contain explosives or not, as might be
considered desirable, and it was not intended to fire it from a cannon,
but to start it on its course from a long semi-cylindrical trough, which
would be used simply to give it the desired direction. After it had been
started by a ram worked by an engine at the rear end of the trough, it
immediately bean to propel itself by means of the mechanism contained
within it.

But the great value of this shell lay in the fact that the moment it
encountered a solid substance or obstruction of any kind its propelling
power became increased. The rings which formed the cone on its forward
end were pressed together, the electric motive power was increased in
proportion to the pressure, and thus the greater the resistance to this
projectile the greater became its velocity and power of progression,
and its onward course continued until its self-containing force had been
exhausted.

The power of explosives had reached, at this period, to so high a point
that it was unnecessary to devise any increase in their enormous energy,
and the only problems before the students of artillery practice related
to methods of getting their projectiles to the points desired. Progress
in this branch of the science had proceeded so far that an attack upon
a f