Its top part forms a box where the air is regulated by a bellows mechanism and can be released only at its proper tension.
In the Rouquayrol device that has been in general use, two india–rubber hoses leave this box and feed to a kind of tent that imprisons the operator's nose and mouth; one hose is for the entrance of air to be inhaled, the other for the exit of air to be exhaled, and the tongue closes off the former or the latter depending on the breather's needs.
But in my case, since I face considerable pressures at the bottom of the sea, I needed to enclose my head in a copper sphere, like those found on standard diving suits, and the two hoses for inhalation and exhalation now feed to that sphere."
"That's perfect, Captain Nemo, but the air you carry must be quickly depleted; and once it contains no more than 15% oxygen, it becomes unfit for breathing."
"Surely, but as I told you, Professor Aronnax, the Nautilus's pumps enable me to store air under considerable pressure, and given this circumstance, the tank on my diving equipment can supply breathable air for nine or ten hours."
"I've no more objections to raise," I replied.
"I'll only ask you, Captain: how can you light your way at the bottom of the ocean?"
"With the Ruhmkorff device, Professor Aronnax.
If the first is carried on the back, the second is fastened to the belt.
It consists of a Bunsen battery that I activate not with potassium dichromate but with sodium.
An induction coil gathers the electricity generated and directs it to a specially designed lantern.
In this lantern one finds a glass spiral that contains only a residue of carbon dioxide gas.
When the device is operating, this gas becomes luminous and gives off a continuous whitish light.
Thus provided for, I breathe and I see."
"Captain Nemo, to my every objection you give such crushing answers, I'm afraid to entertain a single doubt.
However, though I have no choice but to accept both the Rouquayrol and Ruhmkorff devices, I'd like to register some reservations about the rifle with which you'll equip me."
"But it isn't a rifle that uses gunpowder," the captain replied.
"Then it's an air gun?"
"Surely.
How can I make gunpowder on my ship when I have no saltpeter, sulfur, or charcoal?"
"Even so," I replied, "to fire underwater in a medium that's 855 times denser than air, you'd have to overcome considerable resistance."
"That doesn't necessarily follow.
There are certain Fulton–style guns perfected by the Englishmen Philippe–Coles and Burley, the Frenchman Furcy, and the Italian Landi; they're equipped with a special system of airtight fastenings and can fire in underwater conditions.
But I repeat: having no gunpowder, I've replaced it with air at high pressure, which is abundantly supplied me by the Nautilus's pumps."
"But this air must be swiftly depleted."
"Well, in a pinch can't my Rouquayrol tank supply me with more?
All I have to do is draw it from an ad hoc spigot.* Besides, Professor Aronnax, you'll see for yourself that during these underwater hunting trips, we make no great expenditure of either air or bullets."
*Latin: a spigot "just for that purpose."
Ed.
"But it seems to me that in this semidarkness, amid this liquid that's so dense in comparison to the atmosphere, a gunshot couldn't carry far and would prove fatal only with difficulty!"
"On the contrary, sir, with this rifle every shot is fatal; and as soon as the animal is hit, no matter how lightly, it falls as if struck by lightning."
"Why?"
"Because this rifle doesn't shoot ordinary bullets but little glass capsules invented by the Austrian chemist Leniebroek, and I have a considerable supply of them.
These glass capsules are covered with a strip of steel and weighted with a lead base; they're genuine little Leyden jars charged with high–voltage electricity.
They go off at the slightest impact, and the animal, no matter how strong, drops dead.
I might add that these capsules are no bigger than number 4 shot, and the chamber of any ordinary rifle could hold ten of them."
"I'll quit debating," I replied, getting up from the table.
"And all that's left is for me to shoulder my rifle.
So where you go, I'll go."
Captain Nemo led me to the Nautilus's stern, and passing by Ned and Conseil's cabin, I summoned my two companions, who instantly followed us.
Then we arrived at a cell located within easy access of the engine room; in this cell we were to get dressed for our stroll.
Chapter 16 Strolling the Plains
THIS CELL, properly speaking, was the Nautilus's arsenal and wardrobe.
Hanging from its walls, a dozen diving outfits were waiting for anybody who wanted to take a stroll.
After seeing these, Ned Land exhibited an obvious distaste for the idea of putting one on.
"But my gallant Ned," I told him, "the forests of Crespo Island are simply underwater forests!"
"Oh great!" put in the disappointed harpooner, watching his dreams of fresh meat fade away.
"And you, Professor Aronnax, are you going to stick yourself inside these clothes?"
"It has to be, Mr. Ned."
"Have it your way, sir," the harpooner replied, shrugging his shoulders.