The Mediterranean, the blue sea par excellence, "the great sea" of the Hebrews, "the sea" of the Greeks, the "mare nostrum" of the Romans, bordered by orange-trees, aloes, cacti, and sea-pines; embalmed with the perfume of the myrtle, surrounded by rude mountains, saturated with pure and transparent air, but incessantly worked by underground fires; a perfect battlefield in which Neptune and Pluto still dispute the empire of the world!

It is upon these banks, and on these waters, says Michelet, that man is renewed in one of the most powerful climates of the globe. But, beautiful as it was, I could only take a rapid glance at the basin whose superficial area is two million of square yards. Even Captain Nemo's knowledge was lost to me, for this puzzling person did not appear once during our passage at full speed. I estimated the course which the Nautilus took under the waves of the sea at about six hundred leagues, and it was accomplished in forty-eight hours. Starting on the morning of the 16th of February from the shores of Greece, we had crossed the Straits of Gibraltar by sunrise on the 18th.

It was plain to me that this Mediterranean, enclosed in the midst of those countries which he wished to avoid, was distasteful to Captain Nemo. Those waves and those breezes brought back too many remembrances, if not too many regrets. Here he had no longer that independence and that liberty of gait which he had when in the open seas, and his Nautilus felt itself cramped between the close shores of Africa and Europe.

Our speed was now twenty-five miles an hour. It may be well understood that Ned Land, to his great disgust, was obliged to renounce his intended flight. He could not launch the pinnace, going at the rate of twelve or thirteen yards every second. To quit the Nautilus under such conditions would be as bad as jumping from a train going at full speed--an imprudent thing, to say the least of it. Besides, our vessel only mounted to the surface of the waves at night to renew its stock of air; it was steered entirely by the compass and the log.

I saw no more of the interior of this Mediterranean than a traveller by express train perceives of the landscape which flies before his eyes; that is to say, the distant horizon, and not the nearer objects which pass like a flash of lightning.

We were then passing between Sicily and the coast of Tunis. In the narrow space between Cape Bon and the Straits of Messina the bottom of the sea rose almost suddenly. There was a perfect bank, on which there was not more than nine fathoms of water, whilst on either side the depth was ninety fathoms.

The Nautilus had to manoeuvre very carefully so as not to strike against this submarine barrier.

I showed Conseil, on the map of the Mediterranean, the spot occupied by this reef.

"But if you please, sir," observed Conseil, "it is like a real isthmus joining Europe to Africa."

"Yes, my boy, it forms a perfect bar to the Straits of Lybia, and the soundings of Smith have proved that in former times the continents between Cape Boco and Cape Furina were joined."

"I can well believe it," said Conseil.

"I will add," I continued, "that a similar barrier exists between Gibraltar and Ceuta, which in geological times formed the entire Mediterranean."

"What if some volcanic burst should one day raise these two barriers above the waves?"

"It is not probable, Conseil."

"Well, but allow me to finish, please, sir; if this phenomenon should take place, it will be troublesome for M. Lesseps, who has taken so much pains to pierce the isthmus."

"I agree with you; but I repeat, Conseil, this phenomenon will never happen. The violence of subterranean force is ever diminishing. Volcanoes, so plentiful in the first days of the world, are being extinguished by degrees; the internal heat is weakened, the temperature of the lower strata of the globe is lowered by a perceptible quantity every century to the detriment of our globe, for its heat is its life."

"But the sun?"

"The sun is not sufficient, Conseil. Can it give heat to a dead body?"

"Not that I know of."

"Well, my friend, this earth will one day be that cold corpse; it will become uninhabitable and uninhabited like the moon, which has long since lost all its vital heat."

"In how many centuries?"

"In some hundreds of thousands of years, my boy."

"Then," said Conseil, "we shall have time to finish our journey-- that is, if Ned Land does not interfere with it."

And Conseil, reassured, returned to the study of the bank, which the Nautilus was skirting at a moderate speed.

During the night of the 16th and 17th February we had entered the second Mediterranean basin, the greatest depth of which was 1,450 fathoms. The Nautilus, by the action of its crew, slid down the inclined planes and buried itself in the lowest depths of the sea.

On the 18th of February, about three o'clock in the morning, we were at the entrance of the Straits of Gibraltar. There once existed two currents: an upper one, long since recognised, which conveys the waters of the ocean into the basin of the Mediterranean; and a lower counter-current, which reasoning has now shown to exist. Indeed, the volume of water in the Mediterranean, incessantly added to by the waves of the Atlantic and by rivers falling into it, would each year raise the level of this sea, for its evaporation is not sufficient to restore the equilibrium. As it is not so, we must necessarily admit the existence of an under-current, which empties into the basin of the Atlantic through the Straits of Gibraltar the surplus waters of the Mediterranean. A fact indeed; and it was this counter-current by which the Nautilus profited. It advanced rapidly by the narrow pass. For one instant I caught a glimpse of the beautiful ruins of the temple of Hercules, buried in the ground, according to Pliny, and with the low island which supports it; and a few minutes later we were floating on the Atlantic.