“It is actually a manometer. But by communication with the water, whose external pressure it indicates, it gives our depth at the same time.”
“And these other instruments, the use of which I cannot guess?”
“Here, professor, I ought to give you some explanations. Will you be kind enough to listen to me?”
He was silent for a few moments, then he said:
“There is a powerful agent, obedient, rapid, easy, which conforms to every use, and reigns supreme on board my vessel. Everything is done by means of it. It lights it, warms it, and is the soul of my mechanical apparatus. This agent is electricity.”
“Electricity?” I cried in surprise.
“Yes, sir.”
“Nevertheless, captain, you possess an extreme rapidity of movement, which does not agree well with the power of electricity. Until now its dynamic force has remained under restraint, and has only been able to produce a small amount of power.”
“Professor,” said Captain Nemo, “my electricity is not everybody’s. You know what sea-water is composed of. In a thousand grams are found ninety-six and a half per cent. of water, and about two and two-thirds per cent. of chloride of sodium; then, in a smaller quantity, chlorides of magnesium and of potassium, bromide of magnesium, sulphate of magnesia, sulphate and carbonate of lime. You see, then, that chloride of sodium forms a large part of it. So it is this sodium that I extract from sea-water, and of which I compose my ingredients. I owe all to the ocean; it produces electricity, and electricity gives heat, light, motion, and, in a word, life to the Nautilus.”
“But not the air you breathe?”
“Oh, I could manufacture the air necessary for my consumption, but it is useless, because I go up to the surface of the water when I please. However, if electricity does not furnish me with air to breath, it works at least the powerful pumps that are stored in spacious reservoirs, and which enable me to prolong at need, and as long as I will, my stay in the depths of the sea. It gives a uniform and unintermittent light, which the sun does not. Now look at this clock; it is electrical, and goes with a regularity that defies the best chronometers. I have divided it into twenty-four hours, like the Italian clocks, because for me there is neither night nor day, sun nor moon, but only the factitious light that I take with me to the bottom of the sea. Look! just now, it is ten o’clock in the morning.”
“Exactly.”
“Another application of electricity. This dial hanging in front of us indicates the speed of the Nautilus. An electric thread puts it in communication with the screw, and the needle indicates the real speed. Look! now we are spinning along with a uniform speed of fifteen miles an hour.”
“It is marvelous! and I see, captain, you were right to make use of this agent that takes the place of wind, water, and steam.”
“We have not finished, M. Aronnax,” said Captain Nemo, rising; “if you will follow me, we will examine the stern of the Nautilus.”
Really, I knew already the anterior part of this submarine boat, of which this is the exact division, starting from the ship’s head: the dining-room, five yards long, separated from the library by a water-tight partition; the library, five yards long; the large drawing-room, ten yards long, separated from the captain’s room by a second water-tight partition; the said room, five yards in length; mine, two and half yards; and lastly, a reservoir of air, seven and a half yards, that extended to the bows. Total length thirty-five yards, or one hundred and five feet. The partitions had doors that were shut hermetically by means of India-rubber instruments, and they insured the safety of the Nautilus in case of a leak.
I followed Captain Nemo through the waist, and arrived at the center of the boat. There was a sort of well that opened between two partitions. An iron ladder, fastened with an iron hook to the partition, led to the upper end. I asked the captain what the ladder was used for.
“It leads to the small boat,” he said.