CHAPTER FIVE.

THE ENGINEER'S DECLARATION--PENCROFT'S GRAND HYPOTHESIS--AN AERIAL
BATTERY--THE FOUR CANNONS--THE SURVIVING CONVICTS--AYRTON'S HESITATION--
CYRUS HARDING'S GENEROUS SENTIMENTS--PENCROFT'S REGRET.

So, then, all was explained by the submarine explosion of this torpedo.
Cyrus Harding could not be mistaken, as, during the war of the Union, he
had had occasion to try these terrible engines of destruction. It was
under the action of this cylinder, charged with some explosive
substance, nitro-glycerine, picrate, or some other material of the same
nature, that the water of the channel had been raised like a dome, the
bottom of the brig crushed in, and she had sunk instantly, the damage
done to her hull being so considerable that it was impossible to refloat
her. The _Speedy_ had not been able to withstand a torpedo that would
have destroyed an ironclad as easily as a fishing-boat!

Yes! all was explained, everything--except the presence of the torpedo
in the waters of the channel!

"My friends, then," said Cyrus Harding, "we can no longer be in doubt as
to the presence of a mysterious being, a castaway like us, perhaps,
abandoned on our island, and I say this in order that Ayrton may be
acquainted with all the strange events which have occurred during these
two years. Who this beneficent stranger is, whose intervention has, so
fortunately for us, been manifested on many occasions, I cannot imagine.
What his object can be in acting thus, in concealing himself after
rendering us so many services, I cannot understand. But his services
are not the less real, and are of such a nature that only a man
possessed of prodigious power, could render them. Ayrton is indebted to
him as much as we are, for, if it was the stranger who saved me from the
waves after the fall from the balloon, evidently it was he who wrote the
document, who placed the bottle in the channel, and who has made known
to us the situation of our companion. I will add that it was he who
guided that chest, provided with everything we wanted, and stranded it
on Flotsam Point; that it was he who lighted that fire on the heights of
the island, which permitted you to land; that it was he who fired that
bullet found in the body of the peccary; that it was he who immersed
that torpedo in the channel, which destroyed the brig; in a word, that
all those inexplicable events, for which we could not assign a reason,
are due to this mysterious being. Ther