Having died, Ross thought grimly, the Earth had cremated herself.
He did not feel as bad as he had expected to after reading that diary, and realized that discovering the scientific explanation for the surface conditions came as an anticlimax to his first sight of them two months ago. Remembering that constant fog of ash and soot, which had been less dense over the sea and when rain fell, Ross began to form certain conclusions.
Although very finely divided, the ash was heavier than air and its fall was sometimes helped by the rain. When it fell on land it formed a sticky, mud, which, when it had dried out, was blown into the air again. Any that fell into the sea remained there, so that eventually the oceans would absorb it all. Probably the process would take many centuries, but in the end the air would be clear again. The ocean would stay dirty, and there was nothing that Ross could do about it. His final conclusion was that he should return his mind to circumstances over which he had some control, and the sooner the better.
There were three hundred and seventy-two robots, three large repair shops and a considerable variety of spares at his disposal. For Ross’s purpose it wasn’t nearly enough, and so he put the matter to Sister. Because it was only a robot he used simple language, cool logic, and took his argument forward in easy steps. At least, he started that way…
“I am the only human being left in a hospital whose robot staff is trained to care for thousands of patients,” Ross began quietly, “and it follows that, with the exception of yourself and a few Cleaners, the staff will have nothing to do, medically speaking. I have been assured, both by you people and from my reading, that a robot with nothing to do is a very unhappy hunk of machinery indeed. But if I am to keep you busy, if you are to do the jobs I have planned for you, the robot nursing staff will have to learn new skills and subject themselves to drastic physical modifications. They must learn these skills in addition to their existing medical training, because there would be the possibility, a very slim one, I admit, that their medical skill might suddenly be required. Before I go into details, however, are these alterations in structure and programming feasible?”
The robot was silent for about three seconds; then it said, “I have communicated your question to the senior maintenance robot. Structural modifications are no problem, but the ability to learn is governed by the capacity of the memory banks. A full answer is possible only if we know the details of the work you require done.”
“Very well,” said Ross. “Get that maintenance robot down here. I know you can transmit vision as well as sound, but I’d feel more comfortable if he was right here. I’ve some sketches and illustration I want you both to see.”
He went across to his desk, opened the big ledger, which over the months had grown into a cross between a diary and a scrapbook, and sat down. The Ward Sister stood behind him and shortly afterward the maintenance robot squeezed through the door, its blocky, multijointed body making the room seem suddenly crowded.
“What I have in mind is this,” Ross began, without further preamble. “Robots of the Cleaner and Ward Sister type to have their wheels replaced by treads similar to those on the diggers, also whatever modifications necessary added to protect them against rain or drifting ash, so that they can operate for long periods on the surface. I know that they have infrared vision, so that working at night or in bad visibility will not hamper them. In addition I want them fitted with a means of detecting metal, digging it out and transporting it back here. These sketches will show you what I have in mind. But this is only the first step.
“The metal is to build more robots,” Ross continued quickly, “who will go looking for metal to build yet more robots. For my purpose I will require thousands of robots, working hard and continuously, and the metal available in the ruins of the nearer cities will not be sufficient. Eventually we may be forced to mine and process the raw ore. But before that stage is reached I want to have robots searching the ocean bed, and the search extended into other countries by amphibious and airborne models…”
Ross was becoming excited in spite of himself. He was turning pages and jabbing his finger at sketches which he had not meant to discuss at this early stage, and babbling about submarines, helicopters, Archimedes and jet engines. He was leaving his audience behind, yet he couldn’t stop himself. In a disjointed and nearly incoherent way Ross was outlining what was to be his life’s work, the goal which would keep him sane and make him as happy as it was possible to be in his position, and suddenly he could no longer keep his hopes bottled up.
“…I want the whole damned planet searched!” he went on wildly. “Every square foot of it. Somewhere there are other hospitals like this one, perhaps with patients still in Deep Sleep, or undersea bases which survived the war. It happened here so it could happen somewhere else! That is why the search robots must retain their medical knowledge, and extend it wherever possible. The descendants of those survivors are likely to be in bad shape.
“And if you should come on another Deep Sleep patient, I will supervise the awakening…”
Both the robots were ticking at him, a sure sign that they were hopelessly confused. Ross broke off awkwardly, then, in a more subdued voice, began to question the robots regarding the problems of converting his nursing staff to heavy industry.
And there were problems, all right. They lay solidly, one on top of the other, like a brick wall. One of the chief difficulties lay in the limited capacity of the robot brains to store new data. After basic programming a robot possessed the ability to learn by experience — in a very narrow sense, of course — because a small proportion of its memory bank was deliberately left unfilled. But this tiny fraction was not enough to contain data on a whole new specialty, and the result would be a cross between a very smart nurse and a hopelessly stupid miner. The answer was to cancel a large part of its medical programming, but Ross did not want to do that.
Another problem was the difficulty in putting ideas across to the repair robot. To it an illustration was just so many lines on paper; it had no understanding of perspective or of the solidity which they represented. Ross had to go over every line individually, explaining that this one was the radio antenna, that this particular squiggle was the towing hook and this series of parallel lines represented part of the caterpillar treads. Even then he could not make it understand properly. His frustration increased to the point where he felt like shaking it until its insides rattled or going at it with the two-foot wrench in an attempt to beat some sense into it, even though he knew that either course was likely to have the opposite effect. Finally he lost his temper completely and intemperately told it to get out of his sight.
In its maddeningly emotionless voice it requested clarification on the term “hell” and directions for getting there.
Ross closed his notebook and gently thumped the side of his head with a fist. “Why are you so stupid?” he said wearily. “You’re supposed to be the mechanical wizard here, yet Sister, who is only a nurse, seems to get what I’m driving at better than you do—”
“It is a matter of programming, sir,” the Ward Sister broke in. “Maintenance robots cannot abstract data from lines on a chart, such as pulse and temperature graphs, or from X-ray pictures as are the nursing robots—”
“I read circuit diagrams…” began the repair robot.