Airborn by Kenneth Oppel Page A

gas cells. But the sailmakers’ noses are even more sensitive. They patrol the corridors and shafts twenty-four hours a day to make sure every square foot of sail is shipshape. Look.”
    I pointed up through the web of support beams and bracing wires.
    “That’s the axial catwalk up there—do you see it? It runs directly overhead the keel catwalk, right through the ship’s center, from her nose all the way back to her tail. The gas cells hang past it on both sides, like walls. It’s a bit like walking along a tunnel up there.”
    Seventy-five feet above us, through the metal mesh of the catwalk floor, you could see the small silhouettes of a couple sailmakers. I wondered if itwas Lunardi’s boy, up there learning his duties.
    “And higher still?” Kate wanted to know.
    “The gas cells go all the way up to the top, and there are vents to the outside, in case we need to lose some hydrium.”
    “Why would you do that?” she asked, head tilted inquisitively.
    “Well, either to lose some altitude or because we’re beyond pressure height.”
    “What’s that?”
    “Pressure height? Oh, the higher we get, the lower the outside air pressure, so beyond a certain height, the hydrium is at a higher pressure than the air.”
    “Ah, so the hydrium would expand,” said Kate, understanding.
    “Yes, which would rupture the gas cells, so we sometimes have to vent some.”
    “And the outside of the ship, what’s it made of?”
    “Fabric, stretched tight across the alumiron skeleton.”
    “Fabric? That’s all?”
    “Cotton actually. But it’s been specially treated so it’s waterproof and fireproof too.”
    “That’s reassuring, I suppose. And where does that go?” she asked, pointing at a companion ladder.
    “The axial catwalk,” I told her. “There’re three ladders that go up. And from there, you’ve got ladders to the crow’s nests, one fore, one aft.”
    “Really?” she said, intrigued. “What a view that must be.”
    “Especially on a clear night, with the stars and all.”
    “You must know all their names by now.”
    I laughed. “Maybe so.”
    “Can we go up?”
    “Afraid not, miss. It’s crew only up there.”
    “Oh.” She seemed to sag a little. I wished I could have said yes.
    “Are those the engines?” she asked, as the sound of propellers became louder.
    I nodded. “You probably saw them when you boarded. There’s two on either side. I’ll show you.” I turned off the keel catwalk, down a lateral passageway that ended at a hatch in the ship’s hull. The hatch was open, revealing a rectangle of blue sky and sea. We came closer and looked out at the forward port engine car, a large metal pod suspended outside the ship by struts and wires. From the open back of the car whirled an enormous propeller. Like the other three that powered the Aurora , this car was about twenty-five feet long and ten high. A ladderled down to it from the Aurora ’s hatchway. It had railings but no protective cage around it.
    “Very noisy!” Kate shouted at me.
    “Imagine working inside,” I hollered. “The machinists have special leather helmets to block the sound.”
    I’d been inside several times, and it was not a job I ever coveted. It was cold, deafening, boring work, doing watch by the props. I could have told Kate more about the engines themselves, how they ran on Aruba fuel, what horsepower they were and how many rpms they were capable of, but I thought that might bore her.
    “It looks like it could just snap off,” Kate remarked as we walked away from the noise of the engine car back to the keel catwalk.
    “The engine cars are welded on,” I said with a shrug, “as much a part of the Aurora as what we’re standing on.”
    “I won’t think about that too much,” she said. “It doesn’t bother you at all, does it! You seem born to this.”
    “You’re right there,” I said. “I was born on an airship.”
    I’d never been so familiar with a passenger before; I suppose it was