e professor, holding up his hand.

"Undoubtedly," said Captain Vindex calmly. "For a long while nature has
made underneath this tongue of land what men are trying to do now on the
surface."

"Does there exist a passage?"

"Yes, a passage or tunnel, which at fifty feet depth touches a solid
rock."

"How did you discover it--by chance?"

"No," said the captain. "I guessed that such a tunnel existed, and I
have been through it several times."

"Well," said the professor, "we live to learn. Our fathers never dreamed
of gas, of railways, of telegraphs, and I did not suspect the existence
of your wonderful ship."

"Shortly, my dear sir," said the captain, "your children--that is to
say, the next generation--will travel through the air in flying
machines; your railway engines will own electricity as their motive
power. There is no end to scientific discovery; the world is in its
infancy. We are just emerging from barbarism. Wait and watch, that's my
motto. You must not be surprised at anything in these days."

"You are right--we are on the march," said the professor.

The day passed, and at half-past nine the _Searcher_ rose to the surface
to receive her supply of air.

Nothing disturbed the silence but the cry of the pelican and other birds
of the night, with the occasional sound of the escaping steam of a
steamer traveling toward the Far East.

Mont could not rest below, and at once ascended to the platform to
breath the fresh air. In the darkness he saw a pale light, discolored by
the fog, which burned about a mile off.

"A lighthouse," he said.

The captain was by his side, and quietly replied:

"It is the floating lightship of Suez."

"We are near the mouth of the tunnel, I suppose? Is the entrance easy?"

"No," said Captain Vindex, "it is difficult. I always steer the ship
myself, and if you like to come into the wheelhouse with me I will show
you the way. In a moment the _Searcher_ will sink, and we shall not rise
till we are in the Mediterranean."

Mont followed the captain into the pilot's cabin, which was at the bow
of the vessel, the wheel working the rudder by long chains carried aft.

The cabin measured six feet square, four round windows of thick
plate-glass enabled the helmsman to see on all sides, and the electric
light, thrown well forward, made everything as clear as day.

A strong negro, with an eye like a hawk, was at the wheel, but he gave
the spokes to the captain and fell back.