On the morning of 21 October 1966, a wave of coal waste burst out of the hillside above the village of Aberfan. The roar of the mine tip was compared to a low-flying jet aircraft or thunder. The farmhouse with three people inside was smothered first. The wave buried the former, which was full of children answering the register. The tip slide in Aberfan claimed the lives of one hundred and forty-four people, most of them children between the ages of seven and 10.

More or less anyone in a uniform or an official-looking car could get through the roadblock that was set up after the disaster. A green Ford snoozing its way into the village on the morning of 22 October. John Barker, a 42 year old psychiatrist at Shelton hospital, was at the wheel with a keen interest in unusual mental conditions. Barker was dressed in a suit and tie. He was working on a book about whether it was possible to be frightened to death. Barker had heard that a boy had escaped from the school but later died of shock. The doctor came to investigate, but realized he had arrived too soon. When Barker arrived in the village, victims were still being dug out. The loss of life in Aberfan was worse than when Barker was a teenager because it was so concentrated and the dead so young. Most of the people I met had lost someone.

Voyeurs and outsiders were easy to identify. Policemen were shouted at while drinking tea. Someone threw a tobacco tin at the photographer. A steady rain came down, soaking the hundreds of rescuers, muddying the streets, and raising fears that the tip could suddenly fall again, causing another calamity. The village was tense.

The scene at Aberfan, Mid Glamorgan, as rescuers searched for survivors at Pantglas Junior School.

Rescuers search for survivors after a coal waste tip collapsed on Aberfan in October 1966: bereaved families later spoke of dreams and portents before the accident. Photograph: PA

Barker didn't get back in his car and drive away. He was interested in subjects that struck others as strange. He was an orthodox psychiatrist. He studied at the University of Cambridge and St George's Medical School in London. He was not happy with the limits of his field. Barker was a member of Britain's Society for Psychical Research, which was founded in 1882 to investigate the supernatural, and for some years had been interested in the problem of precognition and people who seemed to know what was going to happen to them before it actually did.

Several strange and pathetic incidents connected to the disaster struck him as he talked to witnesses. A school bus carrying children from Merthyr Vale was delayed by fog and reached the site after the tip fell. Their lateness saved them. A boy was sent to school by his mother in tears, apparently for the first time in his life, after he overslept. Inane, unthinking decisions in the moments before the waste came down spared lives and ended others.

Barker was interested in the nature of those decisions. Did people have irrational fears? The dark, unnatural tips above Aberfan had been playing on local people's minds for a long time. The families of the dead spoke of dreams and portents. The drawing of massed figures in the hillside was found by the mother of a boy who died in school.

Barker came up with an idea for a study after his visit to Aberfan. He decided to investigate the people who had premonitions of the disaster and to gather as many as possible of them. Barker wrote to Peter Fairley, the science editor of London's Evening Standard newspaper, asking him to publicise the idea. Fairley carried Barker's appeal in his World of Science column. That is what a senior British psychiatrist would like to know. A vivid dream, a vivid waking impression, and telepathy were some of the visions that Barker was interested in.

For a year, Standard newspaper readers could send in dreams and forebodings, to compare with actual events

Barker received 76 responses to his appeal. Two nights before the disaster, a 63-year-old man named J Arthur Taylor dreamed that he was in Pontypridd, in south Wales. He hadn't been in the town for a long time and was trying to buy a book. He has never seen a computer. I don't know, this may have been one, I looked up and saw a suspended Aberman. This seemed to last a while. Taylor did not know what he was talking about until he heard it on the radio.

In the evening before the coal slide, a spiritualist meeting was held inPlymouth, with a vision from Constance Milder. Milder told six people that she saw an old schoolhouse, a Welsh miner, and a mountain of coal. Rescue operations took place for quite a while. I thought the little boy was left behind and saved. Milder recognised the boy later in the evening.

There was a man in Kent who thought there would be a national disaster on Friday. He told his secretary that he was going to work on that day.

Barker called the percipients and asked for details and witnesses. There was evidence that 22 were described before the mine tip began to move. Barker believed that precognition was not unusual among the general population, and that it might be as common as left-handedness.

In the weeks before Christmas, Charles Wintour, the editor of the Evening Standard, was approached by Fairley and Barker to open a Premonitions Bureau. Readers of the newspaper would be invited to send in their dreams and forebodings, which would be compared with actual events around the world. The experiment was agreed to by Wintour. Five points for unusualness, five points for accuracy, and one point for timing are what Fairley came up with for the predictions.

Illustration of a plane, and mountains behind, and a man wearing glasses with red lenses

In 1902, a young soldier had a vision of a volcano about to explode … and later heard of an eruption that had killed 40,000. Illustration: Deena So’Oteh/The Guardian

The British public has had many attempts to capture their visions. In the late 1920s, an aircraft designer wrote a popular book called An Experiment With Time that combined an account of his own precognitive dreams with a discussion of relativity theory and quantum physics. Dunne was a young soldier in the war when he dreamed of a volcano that would kill 4,000 people. He got hold of the Daily Telegraph, which reported the loss of 40,000 lives after the eruption of Mont Pele, and read about his dream in print.

He was followed for years. Dunne wrote that no one could derive any pleasure from the supposition that he is a freak. Dunne was consoled by advances in quantum mechanics that suggested the old order of time was collapsing.

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Dunne's own theory about how time worked was hard to follow, but An Experiment With Time was influential because it encouraged thousands of readers to keep dream diaries and to see if their presentiments materialised. Dunne said that we should pay attention to trivial flashes of the future as well as important things. He used to sit in the library of his club and pick up a novel, look at the name of the main character and then write down thoughts and images that came to him to see if they predicted the plot. Dunne picked up a book by a popular author, but nothing came to him except a picture of an umbrella on the pavement. Dunne found himself on a bus as it approached the hotel and saw an old lady dressed in a black costume poke a bonnet. She used the umbrella as a walking stick, grasping it as she went. She had it upside down. She was holding it by the end and pounding on the pavement to get to the hotel.

If only one major catastrophe could be shown to have been prevented, the project would justify itself – for all time

Dunne's work was popular in Britain, but 20th-century physics and psychology catalysed similar interest in prophetic dreams elsewhere in Europe. Soon after the Nazis came to power, Charlotte Beradt, a Jewish journalist in Berlin, began writing down the dreams of Germans. Three days after Hitler was elected chancellor, a factory owner dreamed that it took him half an hour to raise his arm in salute. A woman dreamed that the street signs in her neighborhood had been replaced by posters with a list of 20 words that she couldn't say. The list began with Lord and ended with I. The woman dreamed that a squad of policemen hauled her out of a performance of The Magic Flute because a thought-reading machine had registered her. Around 300 dreams were collected by Beradt. The decree of the 17th of this month on the abolition of Walls, a regulation prohibiting Residual Bourgeois Tendencies, prefigured the totalitarian intentions of the regime. A smiling border official threw the lawyer's passport into the snow after he dreamed that he was going to reach the last country on Earth where Jews are still allowed. The land was out of reach. It was 1935.

After the war, Beradt hid her notes in books and posted them to her friends. She wrote in The Third Reich of Dreams that the diaries of the night seemed to record the effects of political events on the mind. They were raw, untouched by hindsight and possibly prophetic for that reason.

When Britain was threatened with invasion in 1940, the playwright JB Priestley delivered regular Sunday evening radio talks on the BBC, called Postscripts, which were heard by a third of the British population. He was from the area. He was longing for a day trip to the seaside. He was also a follower of Dunne.

The playwright traveled to the American west in the early 1930s. He stood by a railing on the South Rim of the Grand Canyon in the mist of the morning. Suddenly the mist lifted, the colors shone and he remembered a vivid dream he had years before, the railing, the sky and the canyon. He had a dream in which the curtain lifted and displayed the same scene as he was sitting in the theatre. The preoccupation with the order of time was one of the themes of Priestley's plays. Jung proposed that events could be linked by meaning rather than cause in the English-speaking world.

In March 1963, a few months before Barker arrived at Shelton, Priestley appeared on the Monitor to talk about time. The beloved national figure was almost 70 years old. He said that each second of our lives was flowing remorselessly, one after the other, until death.

Early and non-western cultures were comfortable with more sophisticated notions of time. He proposed a model of three concurrent times, which was a fusion of Jungian and psychical ideas. Scientists knew that time was unpredictable at both the planetary scale and the subatomic scale because of quantum physics. It should flow through human lives. A world dominated by the worst idea of time men have ever had was described by Priestley.

Man and Time was both a confession and a manifesto. The society was urged to step off the conveyor belt. In 1963, Huw Wheldon invited viewers to send in their own unusual experiences of time. Around a third of the letters came from Dunne's followers.

Illustration of a square walled room with light beams crossing it to panels hanging off the ceiling

In 1930s Berlin, a woman dreamed of a thought-reading machine, and street signs replaced by posters of words it was now forbidden to say. Illustration: Deena So’Oteh/The Guardian

B arker wanted the bureau to be more than anecdotes. The existence of precognition was no longer needed to be proved. Barker claimed in an article for the Medical News in January 1967, that there were more than 10,000 incidents recorded in parapsychology journals.

Barker used the language of seismology to describe mental processes that might be operating at a deep level within the collective subconscious. He wanted an instrument that could capture intimations that were impossible to detect. The public could always write or call if they experienced any premonitions, which they felt were related to future catastrophes. Barker later called the bureau a databank for the nation's dreams and visions.

There might be many false alarms when the operators are inexperienced. The bureau faced a version of the dilemma that haunted Jonah in the Old Testament. The destruction of Nineveh was asked by God. If the people of Nineveh believed his warning and repentance, God would forgive them and Nineveh would not be destroyed. He would look like a fool if his prophecy turned out to be false. He ran away and ended up inside a whale.

There might be no premonitions since no disaster would have occurred. It was worthwhile. If only one major catastrophe could be shown to have been prevented by this means, Barker wrote in a paper for the Society for Psychic.

In the spring of 1967, the bureau got its first major hit. The phone rang in the dining room at Barnfield, Barker's home in the village of Yockleton, at 6am on 21 March. He went upstairs and answered. One of the seers who claimed to experience physical sensations before a disaster was Alan Hencher, a post office switchboard operator.

I was hoping that you wouldn't have to ring me.

Hencher was coming off a night shift and was predicting a plane crash. There were notes on the Shelton hospital letterhead. He was upset. He had a vision of a Caravelle, a French-built passenger jet that was having problems after takeoff. It is going to radio and it is in trouble. There would be 123 or 124 people on the plane and only one would survive. He had a feeling that the crash was going to happen for the last two or three days. It looked like someone was trying to communicate with him. They were trying to make peace. He was directed to the crash by a light that was on and off. The bottom of the page was where Barker's notes ran. On the other side of the paper, he noted that he called Hencher back later for more information, but there was no more.

Wellbeing Sensingdeath web

I knew it was going to happen.

The sun was setting an hour before dawn. Barker passed the prediction on to the Evening Standard after being woken by Hencher. He and Fairley appeared on Late Night Line-Up to promote the bureau. A Britannia passenger aircraft carrying 130 people tried to land in Cyprus during a storm nine days later. Globe Air, a new low-cost Swiss charter airline, had a plane that was on its way from Thailand to Switzerland. The airport in Cairo was closed because of heavy rain when the plane was on its way to its final stop in India. The captain of the plane decided to make an emergency landing in Cyprus despite the bad weather.

The plane was in the air for almost 10 hours before it reached the island. Muller and his co-pilot were three hours over their time limits. The aircraft was cleared to land at Nicosia at 11.10pm, but it came in a little high. Muller asked for permission to make a low circuit of the airport. The control tower saw the plane, its landing lights flashing through the low cloud, before it wheeled to the south and clipped a wing on the side of a hill.

The Evening Standard reported on it's front page the following morning. Two people who survived the initial impact were taken to a UN field hospital, where they died. The Nicosia crash was the sixth worst aviation accident of all time. Both Fairley and Barker noticed similarities with Hencher's prediction. The news coverage of that day included an account of Hencher's premonition. An accompanying photograph showed the Greek Cyprus president picking through the debris.

Illustration of a landline phone hanging down, with curled phone cords alongside it

‘I was hoping not to have to ring you,’ one of the Aberfan seers told the Premonitions Bureau. ‘But now I feel I must.’ Illustration: Deena So’Oteh/The Guardian

He was a gaunt 44-year-old man who lived with his parents in a council house in Essex, now part of London. Before the war, the family moved out of the East End of London. Alan's father was a local government clerk. His mother looked after the couple's three sons. The youngest, Ken, was a professional footballer for Millwall FC in the 50s before becoming a customs and excise official. The odd boy out was Alan, who was once an apprenticeship to an optician. Alan preferred to read while the Hencher family liked to drink. He was personable but serious. He was proud of his collection of books. He was unconscious for four days after a car accident when he was 26. His niece said that he was different to the rest of them.

Fairley tried to call Hencher from the Evening Standard on the day of the plane crash. Barker was going to speak to Hencher the next day. The telephone rang in the dining room again before 1am. Barker came upstairs. The switchboard operator at Shelton was at night. The hospital was trying to reach Barker. The operator wanted to put him through.

When Hencher came on the line, the future of the bureau changed. The psychiatrist wrote in an anguished memo the following day that anyone who plays about with precognition in this way to some extent sticks his neck out and must accept what he gets.

In the dark, Hencher told Barker that he was concerned for his safety. He was worried that there might be an accident. His mind was filled with something black when he thought of Barker. He asked the psychiatrist to check his gas supply. Barnfield did not have a gas supply.

Hencher asked if you have a dark car.

Barker's dog was dark green.

Barker asked if he was telling Hencher that his life was in danger.

The seer said yes.

This is an extract from Sam Knight's book, The Premonitions Bureau. You can support the Guardian and Observer by ordering your copy at guardianbookshop.com. Delivery charges may apply.