gulped audibly. “Carbon monoxide plus iron gives the volatile iron carbonyl.”
“And a robot,” added Powell, “is essentially iron.” Then, grimly: “There’s nothing like deduction. We’ve determined everything about our problem but the solution. We can’t get the selenium ourselves. It’s still too far. We can’t send these robot horses, because they can’t go themselves, and they can’t carry us fast enough to keep us from crisping. And we can’t catch Speedy, because the dope thinks we’re playing games, and he can run sixty miles to our four.”
“If one of us goes,” began Donovan, tentatively, “and comes back cooked, there’ll still be the other.”
“Yes,” came the sarcastic reply, “it would be a most tender sacrifice – except that a person would be in no condition to give orders before he ever reached the pool, and I don’t think the robots would ever turn back to the cliff without orders. Figure it out! We’re two or three miles from the pool – call it two – the robot travels at four miles an hour; and we can last twenty minutes in our suits. It isn’t only the heat, remember. Solar radiation out here in the ultraviolet and below is poison.”
“Um-m-m,” said Donovan, “ten minutes short.”
“As good as an eternity. And another thing, in order for Rule 3 potential to have stopped Speedy where it did, there must be an appreciable amount of carbon monoxide in the metal-vapor atmosphere – and there must be an appreciable corrosive action therefore. He’s been out hours now – and how do we know when a knee joint, for instance, won’t be thrown out of kilter and keel him over. It’s not only a question of thinking – we’ve got to think fast!”
Deep, dark, dank, dismal silence!
Donovan broke it, voice trembling in an effort to keep itself emotionless. He said: “As long as we can’t increase Rule 2 potential by giving further orders, how about working the other way? If we increase the danger, we increase Rule 3 potential and drive him backward.”
Powell’s visiplate had turned toward him in a silent question.
“You see,” came the cautious explanation, “all we need to do to drive him out of his rut is to increase the concentration of carbon monoxide in his vicinity. Well, back at the Station there’s a complete analytical laboratory.”
“Naturally,” assented Powell. “It’s a Mining Station.”
“All right. There must be pounds of oxalic acid for calcium precipitations.”
“Holy space! Mike, you’re a genius.”
“So-so,” admitted Donovan, modestly. “It’s just a case of remembering that oxalic acid on heating decomposes into carbon dioxide, water, and good old carbon monoxide. College chem, you know.”
Powell was on his feet and had attracted the attention of one of the monster robots by the simple expedient of pounding the machine’s thigh.
“Hey,” he shouted, “can you throw?”
“Master?”
“Never mind.” Powell damned the robot’s molasses-slow brain. He scrabbled up a jagged brick-size rock. “Take this,” he said, “and hit the patch of bluish crystals just across the crooked fissure. You see it?”
Donovan pulled at his shoulder. “Too far, Greg. It’s almost half a mile off.”
“Quiet,” replied Powell. “It’s a case of Mercurian gravity and a steel throwing arm. Watch, will you?”
The robot’s eyes were measuring the distance with machinely accurate stereoscopy. His arm adjusted itself to the weight of the missile and drew back. In the darkness, the robot’s motions went unseen, but there was a sudden thumping sound as he shifted his weight, and seconds later the rock flew blackly into the sunlight. There was no air resistance to slow it down, nor wind to turn it aside – and when it hit the ground it threw up crystals precisely in the center of the “blue patch.”
Powell yelled happily and shouted, “Let’s go back after the oxalic acid, Mike.”
And as they plunged into the
“And a robot,” added Powell, “is essentially iron.” Then, grimly: “There’s nothing like deduction. We’ve determined everything about our problem but the solution. We can’t get the selenium ourselves. It’s still too far. We can’t send these robot horses, because they can’t go themselves, and they can’t carry us fast enough to keep us from crisping. And we can’t catch Speedy, because the dope thinks we’re playing games, and he can run sixty miles to our four.”
“If one of us goes,” began Donovan, tentatively, “and comes back cooked, there’ll still be the other.”
“Yes,” came the sarcastic reply, “it would be a most tender sacrifice – except that a person would be in no condition to give orders before he ever reached the pool, and I don’t think the robots would ever turn back to the cliff without orders. Figure it out! We’re two or three miles from the pool – call it two – the robot travels at four miles an hour; and we can last twenty minutes in our suits. It isn’t only the heat, remember. Solar radiation out here in the ultraviolet and below is poison.”
“Um-m-m,” said Donovan, “ten minutes short.”
“As good as an eternity. And another thing, in order for Rule 3 potential to have stopped Speedy where it did, there must be an appreciable amount of carbon monoxide in the metal-vapor atmosphere – and there must be an appreciable corrosive action therefore. He’s been out hours now – and how do we know when a knee joint, for instance, won’t be thrown out of kilter and keel him over. It’s not only a question of thinking – we’ve got to think fast!”
Deep, dark, dank, dismal silence!
Donovan broke it, voice trembling in an effort to keep itself emotionless. He said: “As long as we can’t increase Rule 2 potential by giving further orders, how about working the other way? If we increase the danger, we increase Rule 3 potential and drive him backward.”
Powell’s visiplate had turned toward him in a silent question.
“You see,” came the cautious explanation, “all we need to do to drive him out of his rut is to increase the concentration of carbon monoxide in his vicinity. Well, back at the Station there’s a complete analytical laboratory.”
“Naturally,” assented Powell. “It’s a Mining Station.”
“All right. There must be pounds of oxalic acid for calcium precipitations.”
“Holy space! Mike, you’re a genius.”
“So-so,” admitted Donovan, modestly. “It’s just a case of remembering that oxalic acid on heating decomposes into carbon dioxide, water, and good old carbon monoxide. College chem, you know.”
Powell was on his feet and had attracted the attention of one of the monster robots by the simple expedient of pounding the machine’s thigh.
“Hey,” he shouted, “can you throw?”
“Master?”
“Never mind.” Powell damned the robot’s molasses-slow brain. He scrabbled up a jagged brick-size rock. “Take this,” he said, “and hit the patch of bluish crystals just across the crooked fissure. You see it?”
Donovan pulled at his shoulder. “Too far, Greg. It’s almost half a mile off.”
“Quiet,” replied Powell. “It’s a case of Mercurian gravity and a steel throwing arm. Watch, will you?”
The robot’s eyes were measuring the distance with machinely accurate stereoscopy. His arm adjusted itself to the weight of the missile and drew back. In the darkness, the robot’s motions went unseen, but there was a sudden thumping sound as he shifted his weight, and seconds later the rock flew blackly into the sunlight. There was no air resistance to slow it down, nor wind to turn it aside – and when it hit the ground it threw up crystals precisely in the center of the “blue patch.”
Powell yelled happily and shouted, “Let’s go back after the oxalic acid, Mike.”
And as they plunged into the
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