First published in Fantasy, December 1946
Collected in Reach for Tomorrow
As long as I can remember I have been fascinated by the idea of the Fourth
Dimension. In fact, my very first television programme was devoted to the
subject — 30 minutes live on black and white TV, from Alexandra Palace, in
May 1950!
It was one of those accidents for which no one could be blamed. Richard Nelson had been in and out of the generator pit a dozen times, taking temperature readings to make sure that the unearthly chill of liquid helium was not seeping through the insulation. This was the first generator in the world to use the principle of superconductivity. The windings of the immense stator had been immersed in a helium bath, and the miles of wire now had a resistance too small to be measured by any means known to man.
Nelson noted with satisfaction that the temperature had not fallen further than expected. The insulation was doing its work; it would be safe to lower the rotor into the pit. That thousand-ton cylinder was now hanging fifty feet above Nelson’s head, like the business end of a mammoth drop hammer. He and everyone else in the power station would feel much happier when it had been lowered onto its bearings and keyed into the turbine shaft.
Nelson put away his notebook and started to walk toward the ladder. At the geometric centre of the pit, he made his appointment with destiny.
The load on the power network had been steadily increasing for the last hour, while the zone of twilight swept across the continent. As the last rays of sunlight faded from the clouds, the miles of mercury arcs along the great highways sprang into life. By the million, fluorescent tubes began to glow in the cities; housewives switched on their radio-cookers to prepare the evening meal. The needles of the megawatt meters began to creep up the scales.
These were the normal loads. But on a mountain three hundred miles to the south a giant cosmic ray analyser was being rushed into action to await the expected shower from the new supernova in Capricornus, which the astronomers had detected only an hour beiore. Soon the coils on its five thousand-ton magnets began to drain their enormous currents from the thyratrofl converters.
A thousand miles to the west, fog was creeping toward the greatest airport in the hemisphere. No one worried much about fog, now, when every plane could land on its own radar in zero visibility, but it was nicer not to have it around. So the giant dispersers were thrown into operation, and nearly a thousand megawatts began to radiate into the night, coagulating the water droplets and clearing great swaths through the banks of mist.
The meters in the power station gave another jump, and the engineer on duty ordered the stand-by generators into action. He wished the big, new machine was finished; then there would be no more anxious hours like these. But he thought he could handle the load. Half an hour later the ~eteor0l0gical Bureau put out a general frost warning over the radio. Within sixty seconds, more than a million electric fires were switched on in anticipation. The meters passed the danger mark and went on soaring.
With a tremendous crash three giant circuit breakers leaped from their contacts. Their arcs died under the fierce blast of the helium jets. Three circuits had opened — but the fourth breaker had failed to clear. Slowly, the great copper bars began to glow cherry-red. The acrid smell of burning insulation filled the air and molten metal dripped heavily to the floor below, solidifying at once on the concrete slabs. Suddenly the conductors sagged as the load ends broke away from their supports. Brilliant green arcs of burning copper flamed and died as the circuit was broken. The free ends of the enormous conductors fell perhaps ten feet before crashing into the equipment below. In a fraction of a second they had welded themselves across the lines that led to the new generator.
Forces greater than any yet produced by man were at war in the windings of the machine. There was no resistance to oppose the current, but the inductance of the tremendous windings delayed the moment of peak intensity. The current rose to a maximum in an immense surge that lasted several seconds. At that instant, Nelson reached the centre of the pit.
Then the current tried to stabilise itself, oscillating wildly between narrower and narrower limits. But it never reached its steady state; somewhere, the overriding safety devices came into operation and the circuit that should never have been made was broken again. With a last dying spasm, almost as violent as the first, the current swiftly ebbed away. It was all over.
When the emergency lights came on again, Nelson’s assistant walked to the lip of the rotor pit. He didn’t know what had happened, but it must have been serious. Nelson, fifty feet down, must have been wondering what it was all about.
‘Hello, Dick!’ he shouted. ‘Have you finished? We’d better see what the trouble is.’
There was no reply. He leaned over the edge of the great pit and peered into it. The light was very bad, and the shadow of the rotor made it difficult to see what was below. At first it seemed that the pit was empty, but that
was ridiculous; he had seen Nelson enter it only a few minutes ago. He called again.
‘Hello! You all right, Dick?’
Again no reply. Worried now, the assistant began to descend the ladder. He was halfway down when a curious noise, like a toy balloon bursting very far away, made him look over his shoulder. Then he saw Nelson, lying at the centre of the pit on the temporary woodwork covering the turbine shaft. He was very still, and there seemed something altogether wrong about the angle at which he was lying.
Ralph Hughes, chief physicist, looked up from his littered desk as the door opened. Things were slowly returning to normal after the night’s disasters. Fortunately, the trouble had not affected his department much, for the generator was unharmed. He was glad he was not the chief engineer:
Murdock would still be snowed under with paperwork. The thought gave Dr Hughes considerable satisfaction.
‘Hello, Doc,’ he greeted the visitor. ‘What brings you here? How’s your patient getting on?’
Doctor Sanderson nodded briefly. ‘He’ll be out of hospital in a day or so. But I want to talk to you about him.’
‘I don’t know the fellow — I never go near the plant, except when the Board goes down on its collective knees and asks me to. After all, Murdock’s paid to run the place.’
Sanderson smiled wryly. There was no love lost between the chief engineer and the brilliant young physicist. Their personalities were too different, and there was the inevitable rivalry between theoretical expert and ‘practical’ man.
‘I think this is up your street, Ralph. At any rate, it’s beyond me. You’ve heard what happened to Nelson?’
‘He was inside my new generator when the power was shot into it, wasn’t he?’
‘That’s correct. His assistant found him suffering from shock when the power was cut off again.’
‘What kind of shock? It couldn’t have been electric; the windings are insulated, of course. In any case, I gather that he was in the centre of the pit when they found him.’
‘That’s quite true. We don’t know what happened. But he’s now come round and seems none the worse — apart from one thing.’ The doctor hesitated a moment as if choosing his words carefully.
‘Well, go on! Don’t keep me in suspense!’
‘I left Nelson as soon as I saw he would be quite safe, but about an hour later Matron called me up to say he wanted to speak to me urgently. When I got to the ward he was sitting up in bed looking at a newspaper with a very puzzled expression. I asked him what was the matter. He answered, "Something’s happened to me, Doc." So I said, "Of course it has, but you’ll
be out in a couple of days." He shook his head; I could see there was a worried look in his eyes. He picked up the paper he had been looking at and pointed to it. "I can’t read any more," he said.
‘I diagnosed amnesia and thought: This is a nuisance! Wonder what else be’s forgotten? Nelson must have read my expression, for he went on to say, "Oh, I still know the letters and words — but they’re the wrong way round! I think something must have happened to my eyes." He held up the paper again. "This looks exactly as if I’m seeing it in a mirror," he said. "I can spell out each word separately, a letter at a time. Would you get me a looking glass? I want to try something."
‘I did. He held the paper to the glass and looked at the reflection. Then he started to read aloud, at normal speed. But that’s a trick anyone can learn — compositors have to do it with type — and I wasn’t impressed. On the other hand, I couldn’t see why an intelligent fellow like Nelson should put over an act like that. So I decided to humour him, thinking the shock must have given his mind a bit of a twist. I felt quite certain he was suffering from some delusion, though he seemed perfectly normal.
After a moment he put the paper away and said, "Well, Doc, what do you make of that?" I didn’t know quite what to say without hurting his feelings, so I passed the buck and said, "I think I’ll have to hand you over to Dr Humphries, the psychologist. It’s rather outside my province." Then he made some remark about Dr Humphries and his intelligence tests, from which I gathered he had already suffered at his hands.’
‘That’s correct,’ interjected Hughes. ‘All the men are grilled by the Psychology Department before they join the company. All the same, it’s surprising what gets through,’ he added thoughtfully.
Dr Sanderson smiled, and continued his story.
‘I was getting up to leave when Nelson said, "Oh. I almost forgot. I think j must have fallen on my right arm. The wrist feels badly sprained." "Let’s look at it," I said, bending to pick it up. "No, the other arm," Nelson said, hand held up his left wrist. Still humouring him, I answered, "Have it your own way. But you said your right one, didn’t you?"
Nelson looked puzzled. "So what?" he replied. "This is my right arm. My ~ eyes may be queer, but there’s no argument about that. There’s my wedding ring to prove it. I’ve not been able to get the darned thing off for five years."
‘That shook me rather badly. Because you see, it was his left arm he was holding up, and his left hand that had the ring on it. I could see that what he said was quite true. The ring would have to be cut to get it off again. So said, "Have you any distinctive scars?" He answered. "Not that I can
remember."
‘"Any dental fillings?"’
‘"Yes, quite a few."’
‘We sat looking at each other in silence while a nurse went to fetch Nelson’s records. "Gazed at each other with a wild surmise" is just about how a novelist might put it. Before the nurse returned, I was seized with a
bright idea. It was a fantastic notion, but the whole affair was becoming more and more outrageous. II asked Nelson if I could see the things he had been carrying in his pockets. Here they are.’
Dr Sanderson produced a handful of coins and a small leather-bound diary. Hughes recognised the latter at once as an Electrical Engineer’s Diary; he had one in his own pocket. He took it from the doctor’s hand and flicked it open at random, with that slightly guilty feeling one always has when a stranger’s — still more, a friend’s — diary falls into one’s hands.
And then, for Ralph Hughes, it seemed that the foundations of his world were giving way. Until now he had listened to Dr Sanderson with some detachment, wondering what all the fuss was about. But now the incontrovertible evidence lay in his own hands, demanding his attention and defying his logic.
For he could read not one word of Nelson’s diary. Both the print and the handwriting were inverted, as if seen in a mirror.
Dr Hughes got up from his chair and walked rapidly around the room several times. His visitor sat silently watching him. On the fourth circuit he stopped at the window and looked out across the lake, overshadowed by the immense white wall of the dam. It seemed to reassure him, and he turned to Dr Sanderson again.
‘You expect me to believe that Nelson has been laterally inverted in some way, so that his right and left sides have been interchanged?’
‘I don’t expect you to believe anything. I’m merely giving you the evidence. If you can draw any other conclusion I’d be delighted to hear it. I might add that I’ve checked Nelson’s teeth. All the fillings have been transposed. Explain that away if you can. Those coins are rather interesting, too.’
Hughes picked them up. They included a shilling, one of the beautiful new, beryl-copper crowns, and a few pence and halfpence. He would have accepted them as change without hesitation. Being no more observant than the next man, he had never noticed which way the Queen’s head looked. But the lettering — Hughes could picture the consternation at the Mint if these curious coins ever came to its notice, like the diary, they too had been laterally inverted.
Dr Sanderson’s voice broke into his reverie.
‘I’ve told Nelson not to say anything about this. I’m going to write a full report, it should cause a sensation when it’s published. But we want to know how this has happened. As you are the designer of the new machine, I’ve come to you for advice.’
Dr Hughes did not seem to hear him. He was sitting at his desk with his hands outspread, little fingers touching. For the first time in his life he was thinking seriously about the difference between left and right.
Dr Sanderson did not release Nelson from hospital for several days, during which he was studying his peculiar patient and collecting material for his report. As far as he could tell, Nelson was perfectly normal, apart from his inversion. He was learning to read again, and his progress was
swift after the initial strangeness had worn off. He would probably never again use tools in the same way that he had done before the accident; for the rest of his life, the world would think him left-handed. However, that would not handicap him in any way.
Dr Sanderson had ceased to speculate about the cause of Nelson’s condition. He knew very little about electricity; that was Hughes’s job. He was quite confident that the physicist would produce the answer in due course; he had always done so before. The company was not a philanthropic institution, and it had good reason for retaining Hughes’s services. The new generator, which would be running within a week, was his brain-child, though he had had little to do with the actual engineering details.
Dr Hughes himself was less confident. The magnitude of the problem was terrifying; for he realised, as Sanderson did not, that it involved utterly new regions of science. He knew that there was only one way in which an object could become its own mirror image. But how could so fantastic a theory be proved?
He had collected all available information on the fault that had energised the great armature. Calculations had given an estimate of the currents that ~ had flowed through the coils for the few seconds they had been conducting. But the figures were largely guesswork; he wished he could repeat the experiment to obtain accurate data. It would be amusing to see Murdock’s face if he said, ‘Mind if I throw a perfect short across generators One to Ten sometime this evening?’ No, that was definitely out.
It was lucky he still had the working model. Tests on it had given some ideas of the field produced at the generator’s centre, but their magnitudes were a matter of conjecture. They must have been enormous. It was a miracle that the windings had stayed in their slots. For nearly a month Hughes struggled with his calculations and wandered through regions of atomic physics he had carefully avoided since he left the university. Slowly the complete theory began to evolve in his mind; he was a long way from the final proof, but the road was clear. In another month he would have finished.
The great generator itself, which had dominated his thoughts for the last year, now seemed trivial and unimportant He scarcely bothered to acknowledge the congratulations of his colleagues when it passed its final tests and began to feed its millions of kilowatts into the system. They must have thought him a little strange, but he had always been regarded as somewhat unpredictable. It was expected of him; the company would have been disappointed if its tame genius possessed no eccentricities.
A fortnight later, Dr Sanderson came to see him again. He was in a grave mood.
‘Nelson’s back in the hospital,’ he announced. ‘I was wrong when I said he’d be OK.’
‘What’s the matter with him?’ asked Hughes in surprise.
‘He’s starving to death.’
‘Starving? What on earth do you mean?’
Dr Sanderson pulled a chair up to Hughes’s desk and sat down.
‘I haven’t bothered you for the past few weeks,’ he began, ‘because I knew you were busy on your own theories. I’ve been watching Nelson carefully all this time, and writing up my report. At first, as I told you, he seemed perfectly normal. I had no doubt that everything would be all right.
‘Then I noticed that he was losing weight. It was some time before I was certain of it; then I began to observe other, more technical symptoms. He started to complain of weakness and lack of concentration. He had all the signs of vitamin deficiency. I gave him special vitamin concentrates, but they haven’t done any good. So I’ve come to have another talk with you.’
Hughes looked baffled, then annoyed. ‘But hang it all, you’re the doctor!’
‘Yes, but this theory of mine needs some support. I’m only an unknown medico — no one would listen to me until it was too late. For Nelson is dying, and I think I know why....’
Sir Robert had been stubborn at first, but Dr Hughes had had his way, as he always did. The members of the Board of Directors were even now filing into the conference room, grumbling and generally making a fuss about the extraordinary general meeting that had just been called. Their perplexity was still further increased when they heard that Hughes was going to address them. They all knew the physicist and his reputation, but he was a scientist and they were businessmen. What was Sir Robert planning?
Dr Hughes, the cause of all the trouble, felt annoyed with himself for being nervous. His opinion of the Board of Directors was not flattering, but Sir Robert was a man he could respect, so there was no reason to be afraid of them. It was true that they might consider him mad, but his past record would take care of that. Mad or not, he was worth thousands of pounds to them.
Dr Sanderson smiled encouragingly at him as he walked into the conference room. The smile was not very successful, but it helped. Sir Robert had just finished speaking. He picked up his glasses in that nervous way he had, and coughed deprecatingly. Not for the first time, Hughes wondered how such an apparently timid old man could rule so vast a commercial empire.
‘Well, here is Dr Hughes, gentlemen. He will — ahem — explain everything to you. I have asked him not to be too technical. You are at liberty to interrupt him if he ascends into the more rarefied stratosphere of higher mathematics. Dr Hughes...’
Slowly at first, and then more quickly as he gained the confidence of his audience, the physicist began to tell his story. Nelson’s diary drew a gasp of amazement from the Board, and the inverted coins proved fascinating curiosities. Hughes was glad to see that he had aroused the interest of his listeners. He took a deep breath and made the plunge he had been fearing.
‘You have heard what has happened to Nelson, gentlemen, but what I am going to tell you now is even more startling. I must ask you for your very close attention.’
He picked up a rectangular sheet of notepaper from the conference table, folded it along a diagonal and tore it along the fold.
‘Here we have two right-angled triangles with equal sides. I lay them on the table — so.’ He placed the paper triangles side by side on the table, with their hypotenuses touching, so that they formed a kite-shaped figure. ‘Now, as I have arranged them, each triangle is the mirror image of the other. You can imagine that the plane of the mirror is along the hypotenuse. This is the point I want you to notice. As long as I keep the triangles in the plane of the table, I can slide them around as much as I like, but I can never place one so that it exactly covers the other. Like a pair of gloves, they are not interchangeable although their dimensions are identical.’
He paused to let that sink in. There were no comments, so he continued.
‘Now, if I pick up one of the triangles, turn it over in the air and put it down again, the two are no longer mirror images, but have become completely identical — so.’ He suited the action to the words. ‘This may seem very elementary; in fact, it is so. But it teaches us one very important lesson. The triangles on the table were flat objects, restricted to two dimensions. To turn one into its mirror image I had to lift it up and rotate it in the third dimension. Do you see what I am driving at?’
He glanced round the table. One or two of the directors nodded slowly in dawning comprehension.
‘Similarly, to change a solid, three-dimensional body, such as a man, into its analogue or mirror image, it must be rotated in a fourth dimension. I repeat — a fourth dimension.’
There was a strained silence. Someone coughed, but it was a nervous, not a sceptical cough.
‘Four-dimensional geometry, as you know’ — he’d be surprised if they did — ‘has been one of the major tools of mathematics since before the a time of Einstein. But until now it has always been a mathematical fiction, having no real existence in the physical world. It now appears that the unheard-of currents, amounting to millions of amperes, which flowed momentarily in the windings of our generator must have produced a certain extension into four dimensions, for a fraction of a second and in a 7volume large enough to contain a man. I have been making some calculations and have been able to satisfy myself that a ‘hyperspace’ about ten ket on a side was, in fact, generated: a matter of some ten thousand quartic — not cubic! — feet. Nelson was occupying that space. The sudden collapse of the field when the circuit was broken caused the rotation of e space, and Nelson was inverted.
‘I must ask you to accept this theory, as no other explanation fits the facts. I have the mathematics here if you wish to consult them.
He waved the sheets in front of his audience, so that the directors could he imposing array of equations. The technique worked — it always did.
they cowered visibly. Only McPherson, the secretary, was made of sterner stuff. He had had a semi-technical education and still read a good deal of popular science, which he was fond of airing whenever he had the opportunity. But he was intelligent and willing to learn, and Dr Hughes had often Spent official time discussing some new scientific theory with him.
‘You say that Nelson has been rotated in the Fourth Dimension; but I thought Einstein had shown that the Fourth Dimension was time.’
Hughes groaned inwardly. He had been anticipating this red herring.
‘I was referring to an additional dimension of space,’ he explained patiently. ‘By that I mean a dimension, or direction, at right-angles to our normal three. One can call it the Fourth Dimension if one wishes. With certain reservations, time may also be regarded as a dimension. As we normally regard space as three-dimensional, it is then customary to call time the Fourth Dimension. But the label is arbitrary. As I’m asking you to grant me four dimensions of space, we must call time the Fifth Dimension.
‘Five Dimensions! Good Heavens!’ exploded someone further down the table.
Dr Hughes could not resist the opportunity. ‘Space of several million dimensions has been frequently postulated in sub-atomic physics,’ he said quietly.
There was a stunned silence. No one, not even McPherson, seemed inclined to argue.
‘I now come to the second part of my account,’ continued Dr Hughes. ‘A few weeks after his inversion we found that there was something wrong with Nelson. He was taking food normally, but it didn’t seem to nourish him properly. The explanation has been given by Dr Sanderson, and leads us into the realms of organic chemistry. I’m sorry to be talking like a textbook, but you will soon realise how vitally important this is to the company. And you also have the satisfaction of knowing that we are now all on equally unfamiliar territory.’
That was not quite true, for Hughes still remembered some fragments of his chemistry. But it might encourage the stragglers.
‘Organic compounds are composed of atoms of carbon, oxygen and hydrogen, with other elements, arranged in complicated ways in space. Chemists are fond of making models of them out of knitting needles and coloured plasticine. The results are often very pretty and look like works of advanced art.
‘Now, it is possible to have two organic compounds containing identical numbers of atoms, arranged in such a way that one is the mirror image of the other. They’re called stereo-isomers, and are very common among the sugars. If you could set their molecules side by side, you would see that they bore the same sort of relationship as a right and left glove. They are, in fact, called right — or left-handed — dextro or laevo — compounds. I hope this is quite clear.’
Dr Hughes looked around anxiously. Apparently it was.
‘Stereo-isomers have almost identical chemical properties,’ he went on, ‘though there are subtle differences. In the last few years, Dr Sanderson tells me, it has been found that certain essential foods, including the new class of vitamins discovered by Professor Vandenburg, have properties depending on the arrangement of their atoms in space. In other words, gentlemen, the left-handed compounds might be essential for life, but the
right-handed one would be of no value. This in spite of the fact that their chemical formulae are identical.
‘You will appreciate, now, why Nelson’s inversion is much more serious than we at first thought. It’s not merely a matter of teaching him to read again, in which case — apart from its philosophical interest — the whole business would be trivial. He is actually starving to death in the midst of plenty, simply because he can no more assimilate certain molecules of food than we can put our right foot into a left boot.
‘Dr Sanderson has tried an experiment which has proved the truth of this theory. With very great difficulty, he has obtained the stereo-isomers of many of these vitamins. Professor Vandenburg himself synthesised them when he heard of our trouble. They have already produced a very marked improvement in Nelson’s condition.’
Hughes paused and drew out some papers. He thought he would give the Board time to prepare for the shock. If a man’s life were not at stake, the situation would have been very amusing. The Board was going to be hit where it would hurt most.
‘As you will realise, gentlemen, since Nelson was injured — if you can call it that — while he was on duty, the company is liable to pay for any treatment he may require. We have found that treatment, and you may wonder why I have taken so much of your time telling you about it. The reason is very simple. The production of the necessary stereo-isomers is almost as difficult as the extraction of radium — more so, in some cases. Dr Sanderson tells me that it will cost over five thousand pounds a day to keep Nelson alive.’
The silence lasted for half a minute; then everyone started to talk at once. Sir Robert pounded on the table, and presently restored order. The council of war had begun.
Three hours later, an exhausted Hughes left the conference room and went in search of Dr Sanderson, whom he found fretting in his office.
‘Well, what’s the decision?’ asked the doctor.
‘What I was afraid of. They want me to re-invert Nelson.’
‘Can you do it?’
‘Frankly, I don’t know. All I can hope to do is to reproduce the conditions )f the original fault as accurately I can.’
‘Weren’t there any other suggestions?’
Quite a few; but most of them were stupid. McPherson had the best idea. He wanted to use the generator to invert normal food so that Nelson could at it. I had to point out that to take the big machine out of action for this purpose would cost several millions a year, and in any case the windings wouldn’t stand it more than a few times. So that scheme collapsed. Then Robert wanted to know if you could guarantee there were no vitamins overlooked or that might still be undiscovered. His idea was that in spite of our synthetic diets we might not be able to keep Nelson alive after.’
‘What did you say to that?’
‘I had to admit it was a possibility. So Sir Robert is going to have a talk with Nelson. He hopes to persuade him to risk it; his family will be taken care of if the experiment fails.’
Neither of the two men said anything for a few moments. Then Dr Sanderson broke the silence.
‘Now do you understand the sort of decision a surgeon often has to make,’ he said.
Hughes nodded in agreement. ‘It’s a beautiful dilemma, isn’t it? A perfectly healthy man, but it will cost two millions a year to keep him alive, and we can’t even be sure of that. I know the Board’s thinking of its precious balance sheet more than anything else, but I don’t see any alternative. Nelson will have to take a chance.
‘Couldn’t you make some tests first?’
‘Impossible. It’s a major engineering operation to get the rotor out. We’ll have to rush the experiment through when the load on the system is at minimum. Then we’ll slam the rotor back, and tidy up the mess our artificial short has made. All this has to be done before the peak loads come on again. Poor old Murdock’s mad as hell about it.’
‘I don’t blame him. When will the experiment start?’
‘Not for a few days, at least. Even if Nelson agrees, I’ve got to fix up all my gear.’
No one was ever to know what Sir Robert said to Nelson during the hours they were together. Dr Hughes was more than half prepared for it when the telephone rang and the Old Man’s tired voice said, ‘Hughes? Get your equipment ready. I’ve spoken to Murdock, and we’ve fixed the time for Tuesday night. Can you manage by then?’
‘Yes, Sir Robert.’
‘Good. Give me a progress report every afternoon until Tuesday. That’s all.’
The enormous room was dominated by the great cylinder of the rotor hanging thirty feet above the gleaming plastic floor. A little group of men stood silently at the edge of the shadowed pit, waiting patiently. A maze of temporary wiring ran to Dr Hughes’s equipment — multibeam oscilloscopes, megawattmeters and microchronometers and the special relays that had been constructed to make the circuit at the calculated instant.
That was the greatest problem of all. Dr Hughes had no way of telling when the circuit should be closed; whether it should be when the voltage was at maximum, when it was at zero, or at some intermediate point on the sine wave. He had chosen the simplest and safest course. The circuit would be made at zero voltage; when it opened again would depend on the speed of the breakers.
In ten minutes the last of the great factories in the service area would be closing down for the night. The weather forecast had been favourable; there would be no abnormal loads before morning. By then, the rotor had to be back and the generator running again. Fortunately, the unique method of
construction made it easy to reassemble the machine, but it would be a very close thing and there was no time to lose.
When Nelson came in, accompanied by Sir Robert and Dr Sanderson, he was very pale. He might, thought Hughes, have been going to his execution. The thought was somewhat ill-timed, and he put it hastily aside.
There was just time enough for a last quite unnecessary check of the equipment. He had barely finished when he heard Sir Robert’s quiet voice.
‘We’re ready, Dr Hughes.’
Rather unsteadily, he walked to the edge of the pit. Nelson had already descended, and as he had been instructed, was standing at its exact centre, his upturned face a white blob far below. Dr Hughes waved a brief encouragement and turned away, to rejoin the group by his equipment.
He flicked over the switch of the oscilloscope and played with the synchronising controls until a single cycle of the main wave was stationary on the screen. Then he adjusted the phasing: two brilliant spots of light moved toward each other along the wave until they had coalesced at its geometric centre. He looked briefly toward Murdock, who was watching the megawattme~~~5 intently. The engineer nodded. With a silent prayer, Hughes threw the switch.
There was the tiniest click from the relay unit. A fraction of a second later, the whole building seemed to rock as the great conductors crashed over in the switch room three hundred feet away. The lights faded, and almost died. Then it was all over. The circuit breakers, driven at almost the speed of an explosion, had cleared the line again. The lights returned to normal and the needles of the megawattmeter5 dropped back onto their scales.
The equipment had Withstood the overload. But what of Nelson?
Dr Hughes was surprised to see that Sir Robert, for all his sixty years, had already reached the generator. He was standing by its edge, looking down onto the great pit. Slowly, the physicist went to join him. He was afraid to hurry; a growing sense of premonition was filling his mind. Already he could picture Nelson lying in a twisted heap at the centre of the well, his lifeless eyes staring up at them reproachfully. Then came a still more horrible thought. Suppose the field had collapsed too soon, when the version was only partly completed? In another moment, he would know the worst.
There is no shock greater than that of the totally unexpected, for against the mind has no chance to prepare its defences. Dr Hughes was ready for most anything when he reached the generator. Almost, but not quite.... He did not expect to find it completely empty.
What came after, he could never perfectly remember. Murdock seemed take charge then. There was a great flurry of activity, and the engineers swarmed in to replace the giant rotor. Somewhere in the distance he heard Robert saying, over and over again, ‘We did our best — we did our best.’ must have replied, somehow but everything was very vague....
In the grey hours before the dawn, Dr Hughes awoke from his fitful sleep. All night he had been haunted by his dreams, by weird fantasies of multidimensional geometry. There were visions of strange, other-worldly universes of insane shapes and intersecting planes along which he was doomed to struggle endlessly, fleeing from some nameless terror. Nelson, he dreamed, was trapped in one of those unearthly dimensions, and he was trying to reach him. Sometimes he was Nelson himself, and he imagined that he could see all around him the universe he knew, strangely distorted and barred from him by invisible walls.
The nightmare faded as he struggled up in bed. For a few moments he sat holding his head, while his mind began to clear. He knew what was happening; this was not the first time the solution of some baffling problem had come suddenly upon him in the night.
There was one piece still missing in the jigsaw puzzle that was sorting itself out in his mind. One piece only — and suddenly he had it. There was something that Nelson’s assistant had said, when he was describing the original accident. It had seemed trivial at the time; until now, Hughes had forgotten all about it.
‘When I looked inside the generator, there didn’t seem to be anyone there, so I started to climb down the ladder....
What a fool he had been! Old McPherson had been right, or partly right, after all!
The field had rotated Nelson in the fourth dimension of space, but there had been a displacement in time as well. On the first occasion it had been a matter of seconds only. This time, the conditions must have been different in spite of all his care. There were so many unknown factors, and the theory was more than half guesswork.
Nelson had not been inside the generator at the end of the experiment. But he would be.
Dr Hughes felt a cold sweat break out all over his body. He pictured that thousand-ton cylinder, spinning beneath the drive of its fifty million horsepower. Suppose something suddenly materialised in the space it already occupied....?
He leaped out of bed and grabbed the private phone to the power station. There was no time to lose — the rotor would have to be removed at once. Murdock could argue later.
Very gently, something caught the house by its foundations and rocked it to and fro, as a sleepy child may shake its rattle. Flakes of plaster came planing down from the ceiling; a network of cracks appeared as if by magic in the walls. The lights flickered, became suddenly brilliant, and faded out.
Dr Hughes threw back the curtain and looked toward the mountains. The power station was invisible beyond the foothills of Mount Perrin, but its site was clearly marked by the vast column of debris that was slowly rising against the bleak light of the dawn.