"Suits me."
After climbing through ten trees they began to work their way out to the top of the last one.
When the branches they walked on began to bend, they tied a line to a strong me. Now the sag worked to their advantage, as it opened a window in an otherwise impenetrable wall of foliage. They had chosen a tree that, in a horizontal forest, would have towered above its neighbors. In the spoke it had to be content with jutting further from the wall.
"You were right. It's gone."
"No I wasn't. But it will be in a minute."
Cirocco saw what was left of the hole. It was a tiny black oval in the gray floor, and she could see it contracting like the iris of an eye. From below, the only time they had a good lock at it, that hole had been nearly as large as the spoke itself. Now it was less than ten kilometers across, and still closing. Soon it would seal around the vertical cables that emerged from its center.
"Any ideas?" Gaby asked. "Mat good does it do to close the spoke off from the rim?"
"I haven't the faintest idea. I presume it will open again, though, The angels got through it, they come through regularly, so it..." She paused, and then smiled.
"It's the breath of Gaea."
"Say again?"
"It's what the Titaffides call the wind from the east. Oceanus brings cold weather and the Lament, and Rhea brings hot air and the angels. So you've got a tube 300 kilometers high, with a valve on each end. You could use it as a pump. You could create high and low pressure areas, and use them to move air."
"How would you go about that?" Gaby asked.
"I can think of two ways. Some kind of moveable piston to compress or rarefy the air. I don't see one, and I sure as hell hope there isn't or it'd smear us."
"If there was, it wouldn't have done these trees any good."
"Right. so it's the other method. The walls can expand or contract. Close the bottom valve and open the top one, expand the spoke, and you draw air in from the top. Close the top and open the bottom, put on the big squeeze, and you force it out over the rim."
"Where does the air that comes in the top come from?"
"It's either sucked up through the cables-some of it must be, we saw that-or it comes from the other spokes. They all connect at the top. With a few more valves, you can use the spokes against each other. Open and close a few, and you end up sucking air out of Oceanus, through the hub, and into this spoke. Then open and close some more, and force it down over Rhea. Now if I only knew why the builders thought it was necessary."
Gaby looked thoughtful. "I think I can give you that. It's something that's bothered me. Why doesn't all the air pool at the botton down at the rim? The air's thinner up here, but it's still okay because the air pressure at the rim is higher than Earth-normal. And in low gravity, pressure sure drops off less quickly. Mars' atmosphere isn't much, for instance, but it goes out a long way. Then if you keep the air circulating, it doesn't have time to settle. You can keep adequate air pressure all the way through Gaea."
Cirocco nodded, then sighed. "All right. You've just disposed of the last objection to the climb. We've got food and water, or at least it looks like we will. Now it looks like we'll have air, too. What do you say we get going? "
"How about exploring the rest of the wall?"
"Mat's the use? We might already have passed what we're looking for. There's just no way to see it."
"I guess you're right. Okay, lead on."
The climbing was hard work, tedious, and yet requiring full attention. They got better at it -as they went along, but Cirocco knew it would never get as easy as the climb up the cable.
The one consolation at the end of the first ten-hour climb was that they were in shape. Cirocco was weary and there was a blister on her left palm, but aside from a slight backache she felt all right. It would be good to sleep. They climbed out to the top of a tree for a look down before making camp.
"Will your system measure a height like that?" Gaby frowned, and shook her head.
"Not well." She held her hands out, made a square with them, and squinted. "I'd say-yeow! "
Cirocco grabbed her under one arm, steadying herself by holding a branch over her head.
"Thanks. What a fall that would have been."
"You had your rope," Cirocco pointed out.
"Yeah, but I don't really want to swing on the end of it." She caught her breath, then looked at the ground again.
"What can I say? It's a hell of a lot farther away than it was, and the ceiling ain't a meter closer. It's going to be that way for a long time."
"Would you say three kilometers is about right?"
" I will if you will."
That meant one hundred climbing days, assuming no trouble. Cirocco moaned softly and looked again, trying to believe it was five kilometers but suspecting it was closer to two.
They went back in and found two branches nearly parallel and two and a half meters apart. They slung their hammocks be- tween them, sat on one branch and ate a cold meal of raw vegeta- bles and fruit, then got into the hammocks and strapped themselves in.
Two hours later, it began to rain.
Cirocco woke to a steady dripping on her face, moved her head, and glanced at her watch. It was darker than it had been when she went to sleep. Gaby was snoring quietly, on her side, her face pressed into the webbing. She would have a sore neck in the morning. Cirocco debated waking her but decided that if she could sleep through the rain she was probably better off.
Before moving her hammock, Cirocco edged out to the top of the tree. She could see nothing but a dim wall of mist and a steady downpour. It was raining much harder toward the center. All they were getting at the campsite was the water which gathered on the outer leaves and ran down the limbs.
When she returned Gaby was awake and the dripping was much worse. They decided moving the hammocks would do no good. They got out a tent and, after ripping a few seams with their knives, converted it to a canopy which they tied above the campsite. They dried as best they could and got back into the wet hammocks. The heat and humidity were terrible, but Cirocco was so tired she quickly fell asleep to the sound of water beating on the tarp.
They woke again, shivering, two hours later. "One of those nights," Gaby groaned.
Cirocco's teeth chattered as they unpacked coats and blankets, wrapped themselves tightly, and returned to the ham- mocks. It was half an hour before she felt warm enough to sleep again.
The gentle swaying motion of the trees helped.
Cirocco sneezed, and snow fluttered away. It was very light,, very dry snow, and it had drifted into every crevice of her blanket. She sat up, and it avalanched into her lap.
Icicles hung from the edges of the tarp and the ropes that suspended her hammock. There was a constant cracking sound as wind whipped branches up and down, and a constant clatter of ice hitting the frozen tarp. One of her hands was exposed, and it was stiff and chapped as she reached across the gap and prodded Gaby.
"Huh? Huh?" Gaby looked around with one bleary eye, the other held shut by frozen lashes. "Oh, damn!" She was racked by coughs.
"Are you okay?"
"Except for a frozen ear, I guess so. What now?"
"Put on everything we have, I guess. Then wait it out."
It was hard to do, sitting in a hammock, but they managed it. There was one disaster as Cirocco fumbled with numb fingers, then saw a glove quickly vanish in the swirling snow beneath them. She cursed for five minutes before recalling they still had Gene's gloves.
Then they waited.
Sleep was impossible. They were warm enough in the layers of clothing and blankets, but they wished for face masks and goggles. Every ten minutes they shook the accumulation of snow from their bodies.