section alone could carry over twenty tons, and it would be some time before they unloaded that weight of equipment on the site.
Satisfied with this stage of the project, Lawrence left the Embarkation Building while his assistants were still dismantling the raft. Five minutes later (that was one advantage of Port Roris—you could get anywhere in five minutes), he was in the local engineering depot. What he found there was not quite so satisfactory.
Supported on a couple of trestles was a two-meter-square mock-up of Selene's roof—an exact copy of the real thing, made from the same materials. Only the outer sheet of aluminized fabric that served as a sun shield was missing; it was so thin and flimsy that it would not affect the test.
The experiment was an absurdly simple one, involving only three ingredients: a pointed crowbar, a sledge hammer, and a frustrated engineer, who, despite strenuous efforts, had not yet succeeded in hammering the bar through the roof.
Anyone with a little knowledge of lunar conditions would have guessed at once why he had failed. The hammer, obviously, had only a sixth of its terrestrial weight; therefore-equally obviously—it was that much less effective.
The reasoning would have been completely false. One of the hardest things for the layman to understand was the difference between weight and mass, and the inability to do so had led to countless accidents. For weight was an arbitrary characteristic; you could change it by moving from one world to another. On Earth, that hammer would weigh six times as much as it did here; on the sun, it would be almost two hundred times heavier; and in space it would weigh nothing at all.
But in all three places, and indeed throughout the Universe, its mass or inertia would be exactly the same. The effort needed to set it moving at a certain speed, and the impact it would produce when stopped, would be constant through all space and time. On a nearly gravityless asteroid, where it weighed less than a feather, that hammer would pulverize a rock just as effectively as on Earth.
“What's the trouble?” said Lawrence .
“The roof's too springy,” explained the engineer, rubbing the sweat from his brow. “The crowbar just bounces back every time it's hit.”
“I see. But will that happen when we're using a fifteen-meter pipe, with dust packed all around it? That may absorb the recoil.”
“Perhaps—but look at this.”
They kneeled beneath the mock-up and inspected the underside of the roof. Chalk lines had been drawn upon it to indicate the position of the electric wiring, which had to be avoided at all costs.
“This Fiberglas is so tough, you can't make a clean hole through it. When it does yield, it splinters and tears. See-it's already begun to star. I'm afraid that if we try this bruteforce approach, we'll crack the roof.”
“And we can't risk that,” Lawrence agreed. “Well, drop the idea. If we can't pile drive, we'll have to bore. Use a drill, screwed on the end of the pipe so it can be detached easily. How are you getting on with the rest of the plumbing?”
“Almost ready—it's all standard equipment. We should be finished in two or three hours.”
“I'll be back in two,” said Lawrence . He did not add, as some men would have done, “I want it finished by then.” His staff was doing its utmost, and one could neither bully nor cajole trained and devoted men into working faster than their maximum. Jobs like this could not be rushed, and the deadline for Selene's oxygen supply was still three days away. In a few hours, if all went well, it would have been pushed into the indefinite future.
Unfortunately, all was going very far from well.
Commodore Hansteen was the first to recognize the slow, insidious danger that was creeping up upon them. He had met it once before, when he had been wearing a faulty space suit on Ganymede-an incident he had no wish to recall, but had never really forgotten.
“Pat,” he said quietly, making sure that no one could overhear. “Have you noticed any difficulty in breathing?”
Pat looked startled, then answered, “Yes, now that you mention it. I'd put it down to the heat.”
“So did I at first. But I know these symptoms—especially the quick breathing. We're running into carbon- dioxide poisoning.”
“But that's ridiculous. We should be all right for another three days-unless something has gone wrong with the air purifiers.”
“I'm afraid it has. What system do we use to get rid of the carbon dioxide?”
“Straight chemical absorption. It's a very simple, reliable setup; we've never had any trouble with it before.”
“Yes, but it's never had to work under these conditions before. I think the heat may have knocked out the chemicals. Is there any way we can check them?”
Pat shook his head.
“No. The access hatch is on the outside of the hull.”
“Sue, my dear,” said a tired voice which they hardly recognized as belonging to Mrs. Schuster, “do you have anything to fix a headache?”
“If you do,” said another passenger, “I'd like some as well.”
Pat and the Commodore looked at each other gravely. The classic symptoms were developing with textbook precision.
“How long would you guess?” said Pat quietly.
“Two or three hours at the most. And it will be at least six before Lawrence and his men can get here.”
It was then that Pat knew, without any further argument, that he was genuinely in love with Sue. For his first reaction was not fear for his own safety, but anger and grief that, after having endured so much, she would have to die within sight of rescue.
CHAPTER 18
When Tom Lawson woke up in that strange hotel room, he was not even sure who he was, still less where he was. The fact that he had some weight was his first reminder that he was no longer on Lagrange-but he was not heavy enough for Earth. Then it was not a dream; he was on the Moon, and he really had been out into that deadly Sea of Thirst .
And he had helped to find Selene; twenty-two men and women now had a chance of life, thanks to his skill and science. After all the disappointments and frustrations, his adolescent dreams of glory were about to come true. Now the world would have to make amends to him for its indifference and neglect.
The fact that society had provided him with an education which, a century earlier, only a few men could afford did nothing to alleviate Tom's grudge against it. Such treatment was automatic in this age, when every child was educated to the level that his intelligence and aptitudes permitted. Now that civilization needed all the talent that it could find, merely to maintain itself, any other educational policy would have been suicide. Tom gave no thanks to society for providing the environment in which he had obtained his doctor's degree; it had acted in its own self-interest.
Yet this morning he did not feel quite so bitter about life or so cynical about human beings. Success and recognition are great emollients, and he was on his way to achieving both. But there was more to it than that; he had glimpsed a deeper satisfaction. Out there on Duster Two, when his fears and uncertainties had been about to overwhelm him, he had made contact with another human being, and had worked in successful partnership with a man whose skill and courage he could respect.
It was only a tenuous contact, and, like others in the past, it might lead nowhere. A part of his mind, indeed, hoped that it would, so that he could once again assure himself that all men were selfish, sadistic scoundrels. Tom could no more escape from his early boyhood than Charles Dickens, for all his success and fame, could escape the shadows of the blacking factory that had both metaphorically and literally darkened his youth. But he had made a
