undo the bolts, and the little boat goes up to the surface of the sea with prodigious rapidity. I then open the panel of the bridge, carefully shut till then; I mast it, hoist my sail, take my oars, and I'm off."
"But how do you get back on board?"
"I do not come back, M. Aronnax; the Nautilus comes to me."
"By your orders?"
"By my orders. An electric thread connects us. I telegraph to it, and that is enough."
"Really," I said, astonished at these marvels, "nothing can be more simple."
After having passed by the cage of the staircase that led to the platform, I saw a cabin six feet long, in which Conseil and Ned Land, enchanted with their repast, were devouring it with avidity. Then a door opened into a kitchen nine feet long, situated between the large store-rooms. There electricity, better than gas itself, did all the cooking. The streams under the furnaces gave out to the sponges of platina a heat which was regularly kept up and distributed. They also heated a distilling apparatus, which, by evaporation, furnished excellent drinkable water. Near this kitchen was a bathroom comfortably furnished, with hot and cold water taps.
Next to the kitchen was the berth-room of the vessel, sixteen feet long. But the door was shut, and I could not see the management of it, which might have given me an idea of the number of men employed on board the Nautilus.
At the bottom was a fourth partition that separated this office from the engine-room. A door opened, and I found myself in the compartment where Captain Nemo—certainly an engineer of a very high order—had arranged his locomotive machinery. This engine-room, clearly lighted, did not measure less than sixty-five feet in length. It was divided into two parts; the first contained the materials for producing electricity, and the second the machinery that connected it with the screw. I examined it with great interest, in order to understand the machinery of the Nautilus.
"You see," said the Captain, "I use Bunsen's contrivances, not Ruhmkorff's. Those would not have been powerful enough. Bunsen's are fewer in number, but strong and large, which experience proves to be the best. The electricity produced passes forward, where it works, by electro-magnets of great size, on a system of levers and cog-wheels that transmit the movement to the axle of the screw. This one, the diameter of which is nineteen feet, and the thread twenty-three feet, performs about 120 revolutions in a second."
"And you get then?"
"A speed of fifty miles an hour."
"I have seen the Nautilus manoeuvre before the Abraham Lincoln, and I have my own ideas as to its speed. But this is not enough. We must see where we go. We must be able to direct it to the right, to the left, above, below. How do you get to the great depths, where you find an increasing resistance, which is rated by hundreds of atmospheres? How do you return to the surface of the ocean? And how do you maintain yourselves in the requisite medium? Am I asking too much?"
"Not at all, Professor," replied the Captain, with some hesitation; "since you may never leave this submarine boat. Come into the saloon, it is our usual study, and there you will learn all you want to know about the Nautilus."
CHAPTER XII
SOME FIGURES
A moment after we were seated on a divan in the saloon smoking. The Captain showed me a sketch that gave the plan, section, and elevation of the Nautilus. Then he began his description in these words:
"Here, M. Aronnax, are the several dimensions of the boat you are in. It is an elongated cylinder with conical ends. It is very like a cigar in shape, a shape already adopted in London in several constructions of the same sort. The length of this cylinder, from stem to stern, is exactly 232 feet, and its maximum breadth is twenty-six feet. It is not built quite like your long-voyage steamers, but its lines are sufficiently long, and its curves prolonged enough, to allow the water to slide off easily, and oppose no obstacle to its passage. These two dimensions enable you to obtain by a simple calculation the surface and cubic contents of the Nautilus. Its area measures 6,032 feet; and its contents about 1,500 cubic yards; that is to say, when completely immersed it displaces 50,000 feet of water, or weighs 1,500 tons.
"When I made the plans for this submarine vessel, I meant that nine-tenths should be submerged: consequently it ought only to displace nine-tenths of its bulk, that is to say, only to weigh that number of tons. I ought not, therefore, to have exceeded that weight, constructing it on the aforesaid dimensions.
"The Nautilus is composed of two hulls, one inside, the other outside, joined by T-shaped irons, which render it very strong. Indeed, owing to this cellular arrangement it resists like a block, as if it were solid. Its sides cannot yield; it coheres spontaneously, and not by the closeness of its rivets; and its perfect union of the materials enables it to defy the roughest seas.
"These two hulls are composed of steel plates, whose density is from .7 to .8 that of water. The first is not less than two inches and a half thick and weighs 394 tons. The second envelope, the keel, twenty inches high and ten thick, weighs only sixty-two tons. The engine, the ballast, the several accessories and apparatus appendages, the partitions and bulkheads, weigh 961.62 tons. Do you follow all this?"
"I do."
"Then, when the Nautilus is afloat under these circumstances, one-tenth is out of the water. Now, if I have made reservoirs of a size equal to this tenth, or capable of holding 150 tons, and if I fill them with water, the boat, weighing then 1,507 tons, will be completely immersed. That would happen, Professor. These reservoirs are in the lower part of the Nautilus. I turn on taps and they fill, and the vessel sinks that had just been level with the surface."
"Well, Captain, but now we come to the real difficulty. I can understand your rising to the surface; but, diving below the surface, does not your submarine contrivance encounter a pressure, and consequently undergo an upward thrust of one atmosphere for every thirty feet of water, just about fifteen pounds per square inch?"
"Just so, sir."
"Then, unless you quite fill the Nautilus, I do not see how you can draw it down to those depths."
"Professor, you must not confound statics with dynamics or you will be exposed to grave errors. There is very little labour spent in attaining the lower regions of the ocean, for all bodies have a tendency to sink. When I wanted to find out the necessary increase of weight required to sink the Nautilus, I had only to calculate the reduction of volume that sea-water acquires according to the depth."
"That is evident."
"Now, if water is not absolutely incompressible, it is at least capable of very slight compression. Indeed, after the most recent calculations this reduction is only .000436 of an atmosphere for each thirty feet of depth. If we want to sink 3,000 feet, I should keep account of the reduction of bulk under a pressure equal to that of a column of water of a thousand feet. The calculation is easily verified. Now, I have supplementary reservoirs capable of holding a hundred tons. Therefore I can sink to a considerable depth. When I wish to rise to the level of the sea, I only let off the water, and empty all the reservoirs if I want the Nautilus to emerge from the tenth part of her total capacity."
I had nothing to object to these reasonings.
"I admit your calculations, Captain," I replied; "I should be wrong to dispute them since daily experience confirms them; but
