know those little frequented and almost forgotten islands opposite
Sicily?

"I know all about all of them," replied the sailor boastfully. And
without realizing exactly whether it was curiosity on the part of the
listener, or whether he was being submitted to an interesting
examination, he talked on and on.

He was well acquainted with the archipelago of the Lipari Islands with
their mines of sulphur and pumice-stone,--a group of volcanic peaks
which rise up from the depths of the Mediterranean. In these the
ancients had placed Aeolus, lord of the winds; in these was Stromboli,
vomiting forth enormous balls of lava which exploded with the roar of
thunder. Its volcanic slag fell again into the chimneys of the crater
or rolled down the mountain slopes, falling into the waves.

More to the west, isolated and solitary in a sea free from shoals, was
Ustica,--an abrupt and volcanic island that the Phoenicians had
colonized and which had served as a refuge for Saracen pilots. Its
population was scant and poor. There was nothing to see on it, apart
from certain fossil shells interesting to men of science.

But the count showed himself wonderfully interested in this extinct and
lonely crater in the midst of a sea frequented only by fishing smacks.

Ferragut had also seen, although far off, at the entrance of the harbor
of Trapani, the archipelago of the Aegadian Islands where are the great
fishing grounds of the tunny. Once he had disembarked in the island of
Pantellaria, situated halfway between Sicily and Africa. It was a very
high, volcanic cone that came up in the midst of the strait and had at
its base alkaline lakes, sulphurous fumes, thermal waters, and
prehistoric constructions of great stone blocks similar to those in
Sardinia and the Balearic Islands. Boats bound for Tunis and Tripoli
used to carry cargoes of raisins, the only export from this ancient
Phoenician colony.

Between Pantellaria and Sicily the ocean floor was considerably
elevated, having on its back an aquatic layer that in some points was
only twelve yards thick. It was the great shoal called the Aventura, a
volcanic swelling, a double submerged island, the submarine pedestal of
Sicily.

The ledge of Aventura also appeared to interest the count greatly.

"You certainly know the sea well," he said in an approving tone.

Ferragut was about to go on talking when the two ladies entered with a
tray which contained the tea service and various plates