wreck was cast up on the beach.

As to the papers on board, it is useless to say that, although he
carefully searched the lockers of the poop, Harding did not discover any
trace of them. The pirates had evidently destroyed everything that
concerned either the captain or the owners of the _Speedy_, and, as the
name of her port was not painted on her counter, there was nothing which
would tell them her nationality. However, by the shape of her boats
Ayrton and Pencroft believed that the brig was of English build.

A week after the catastrophe--or, rather, after the fortunate, though
inexplicable, event to which the colony owed its preservation--nothing
more could be seen of the vessel, even at low tide. The wreck had
disappeared, and Granite House was enriched by nearly all it had
contained.

However, the mystery which enveloped its strange destruction would
doubtless never have been cleared away if, on the 30th of November, Neb,
strolling on the beach, had not found a piece of a thick iron cylinder,
bearing traces of explosion. The edges of this cylinder were twisted
and broken, as if they had been subjected to the action of some
explosive substance.

Neb brought this piece of metal to his master, who was then occupied
with his companions in the workshop of the Chimneys.

Cyrus Harding examined the cylinder attentively, then, turning to
Pencroft--

"You persist, my friend," said he, "in maintaining that the _Speedy_ was
not lost in consequence of a collision?"

"Yes, captain," answered the sailor. "You know as well as I do that
there are no rocks in the channel."

"But suppose she had run against this piece of iron?" said the engineer,
showing the broken cylinder.

"What, that bit of pipe!" exclaimed Pencroft in a tone of perfect
incredulity.

"My friends," resumed Harding, "you remember that before she foundered
the brig rose on the summit of a regular water-spout?"

"Yes, captain," replied Herbert.

"Well, would you like to know what occasioned that water-spout? It was
this," said the engineer, holding up the broken tube.

"That?" returned Pencroft.

"Yes! This cylinder is all that remains of a torpedo!"

"A torpedo!" exclaimed the engineer's companions.

"And who put the torpedo there?" demanded Pencroft, who did not like to
yield.

"All that I can tell you is, that it was not I," answered Cyrus Harding;
"but it was there, and you have been able to judge of its incomparable
power!"