And while the monorail ran on toward Farside, Maclaren left the Interhuman language quite behind him. Ryerson could follow tensors, even when scribbled on a menu, but Maclaren had some new function, symbolized by a pneumatic female outline, that reduced to a generalized tensor under certain conditions. Ryerson stepped out on Farside, two hours later, with his brain rotating.

He had heard of the cyclopean installations which fill the whole of Yukawa Crater and spread out onto the plains beyond. Who has not? But all he saw on his first visit was a gigantic concourse, a long slideway tunnel, and a good many uniformed technicians. He made some timid mention of his disappointment to Maclaren. The New Zealander nodded: “Exactly. There’s more romance, more sense of distance covered, and a devil of a lot better scenery, in an afternoon on the bay, than in a fifty light-year leap. I say space travel is overrated. And it’s a fact, I’ve heard, that spacemen themselves prefer the interplanetary runs. They take the dull interstellar watches as a matter of duty, by turns.”

Here and there the tunnel branched off, signs indicating the way to Alpha Centauri Jump, Tau Ceti Jump, Epsilon Eridani Jump, all the long-colonized systems. Those were for passengers; freight went by other beams. There was no great bustle along any of the tubes. Comparatively few Earthlings had occasion to visit outsystem on business; still fewer could afford it for pleasure, and of course no colonial came here without a grudging O.K. The Protector had trouble enough; he was not going to expose the mother planet and its restless billions to new ideas born under new skies, nor let any more colonials than he could help see first-hand what an inferior position they held. That was the real reason for the ban, every educated Terrestrial knew as much. The masses, being illiterate, swallowed a vague official excuse about trade policy.

The branches leading to Sirius Jump, Procyon Jump, and the other attained but uncolonizable systems, were almost deserted. Little came from such places — perhaps an occasional gem or exotic chemical. But relay stations had been established there, for ‘casting to more useful planets.

Ryerson’s heart leaped when he passed a newly activated sign: an arrow and WASHINGTON 5584 JUMP burning above. That tunnel would be filled, come next week!

He should have been in the line. And Tamara. Well, there would be later waves. His passage was already paid for, he had had no difficulty about transferring to another section.

To make conversation, he said through a tightness: “Where are the bulkheads?”

“Which ones?” asked Maclaren absently.

“Safety bulkheads. A receiver does fail once in a great while, you know. That’s why the installations here are spread out so much, why every star has a separate ‘caster. There’s a vast amount of energy involved in each transmission — one reason why a ‘casting is more expensive than transportation by spaceship. Even a small increment, undissipated, can melt a whole chamber.”

“Oh, yes. That.” Maclaren had let Ryerson get pompous about the obvious because it was plain he needed something to bolster himself. What itched the kid, anyhow? One should think that when the Authority offered a fledgling a post on an expedition as fundamental as this — Of course, it had upset Ryerson’s plans of emigration. Rut not importantly. There was no danger he would find all the choice sites on Rama occupied if he came several weeks late: too few people had the fare as it was.

Maclaren said, “I see what you mean. Yes, the bulkheads are there, but recessed into the walls and camouflaged. You don’t want to emphasize possible danger to the cash customers, eh? Some technic might get annoyed and make trouble.”

“Some day,” said Ryerson, “they’ll reduce the energy margin needed; and they’ll figure how to reproduce a Frank tube, rather than manufacture it. Record the pattern and recreate from a matter bank. Then anyone can afford to ride the beams. Interplanetary ships, even air and surface craft, will become obsolete.”

Maclaren made no answer. He had sometimes thought, more or less idly, about the unrealized potentialities of matter-casting. Hard to say whether personal immortality would be a good thing or not. Not for the masses, surely! Too many of them as it was. But a select few, like Terangi Maclaren — or was it worth the trouble? Even given boats, chess, music, the-No Drama, beautiful women and beautiful spectroscopes, life could get heavy.

As for matter transmission, the difficulty and hence the expense lay in the complexity of the signal. Consider an adult human. There are some 1014 cells in him, each an elaborate structure involving many proteins with molecular weights in the millions. You had to scan every one of those molecules — identify it structurally, ticket its momentary energy levels, and place it in proper spatio-temporal relationship to every other molecule — as nearly simultaneously as the laws of physics permitted. You couldn’t take a man apart, or reassemble him, in more than a few microseconds; he wouldn’t survive it. You couldn’t even transmit a recognizable beefsteak in much less of a hurry.

So the scanning beam went through and through, like a blade of energy. It touched every atom in its path, was modified thereby, and flashed that modification onto the transmitter matrix. But such fury destroyed. The scanned object was reduced to gas so quickly that only an oscilloscope could watch the process. The gas was sucked into the destructor chamber and atomically condensed in the matter bank; in time it would become an incoming passenger, or incoming freight. In a sense, the man had died.

If you could record the signal which entered the transmitter matrix — you could keep such a record indefinitely, recreate the man and his instantaneous memories, thoughts, habits, prejudices, hopes and loves and hates and horrors, a thousand years afterward. You could create a billion identical men. Or, more practically, a single handmade prototype could become a billion indistinguishable copies; nothing would be worth more than any handful of dirt. Or… superimpose the neurone trace-patterns, memories, of a lifetime, onto a recorded twenty-year-old body, be born again and live forever!

The signal was too complex, though. An unpromising research program went on. Perhaps in a few centuries they would find some trick which would enable them to record a man, or even a Frank tube. Meanwhile, transmission had to be simultaneous with scanning. The signal went out. Probably it would be relayed a few times. Eventually the desired receiving chamber got it. The receiver matrix, powered by dying atomic nuclei, flung gases together, formed higher elements, formed molecules and cells and dreams according to the signal, in microseconds. It was designed as an energy-consuming process, for obvious reasons: packing fraction energy was dissipated in gravitic and magnetic fields, to help shape the man. (Or the beefsteak, or the spaceship, or the colonial planet’s produce.) He left the receiving chamber and went about his business.

A mono-isotopic element is a simple enough signal to record, Maclaren reminded himself, though even that requires a houseful of transistor elements. So this civilization can afford to be extravagant with metals — can use pure mercury as the raw material of a spaceship’s blast, for instance. But we still eat our bread in the sweat of some commoner’s brow.

Not for the first time, but with no great indignation — life was too short for anything but amusement at the human race — Maclaren wondered if the recording problem really was as difficult as the physicists claimed. No government likes revolutions, and molecular duplication would revolutionize society beyond imagining. Just think how they had to guard the stations as it was, and stick them out here on the Moon …otherwise, even today, some fanatic could steal a tube of radium from a hospital and duplicate enough to sterilize a planet!