Although the cave is full of rats that often crawl over him, he is unfazed.
A wiry, red-bearded man of 52 with tousled white hair, Slater is, as one might guess, an eccentric - living proof that Britain is still the homeland of that strange and storied species. In fact, argues Edinburgh psychologist David J. Weeks, Britain is now experiencing "a great modern renaissance of eccentricity."
Weeks, convinced that eccentrics are the "last category of people" to elude scholarly investigation, uncovered 130 of them while researching a new, serious and thus curiously dull book on the subject, Eccentrics: The Scientific Investigation.
Only one of the people he studied turned out to be a full-blown psychotic. The rest were, well, eccentric, pursuing bizarre interests to the point of obsession.
He found a marathon tricyclist who lives in a bomb-battered house in Belfast; a woman who has planted 7,000 pixies and gnomes in her garden; a man who drove backward from Sheffield to Huddersfield, a distance of nearly 30 miles, and a whole bevy of people who dress like Robin Hood. One merry man regularly carries a longbow and lives in the forest.
Another eccentric is a potato fanatic who not only examines potatoes as a profession (he is an inspector for Scotland's Department of Agriculture and Fisheries), but also survives by eating nothing but potatoes (except for the occasional candy bar and vitamin). He even spends his holidays in Peru, the better to spy the spud in its native habitat.
Altogether, Weeks estimated, 1 in every 10,000 people in Britain is an eccentric. And he believes that there are more here than elsewhere because the population greets the harmlessly bizarre with relative equanimity. After all, Sunday Sport, one of Britain's best-selling newspapers, recently reported that a B-52 bomber had landed on the moon.
"Now that's going a bit far," chortled John Ward, another of Weeks' subjects, who enjoys rappelling down the sides of tall buildings dressed in an elephant costume ("It seemed like fun"), once attempted to pedal a paddle boat across the English Channel ("The ferry was too dear"), and is the proud inventor of a combination bicycle-stepladder ("In case you want to take a closer look while pedaling about").
Eccentricity is not a bad thing at all, concluded Weeks, but a creative endeavor that can lead to discoveries, inventions and works of art that benefit mankind. The eccentric, he maintained, is "a potent symbol of unfettered freedom of spirit, inquiry and change."
Rock star Elton John, for the record, is not a true eccentric, according to Weeks. He may own a lot of eyeglasses and wear weird hats and wigs, but in true eccentrics, Weeks contended, "the dividing line between the act and the person has been long lost. . . . A true eccentric is never acting."
Among all the people Weeks interviewed, Slater was a standout.
"I decided years ago I didn't want to be normal," Slater said. "You've got a choice. You're born with a free will and you can do what the hell you like."
His exploits have hardly been normal. He once walked the entire length of Britain - from John O'Groats in the north of Scotland to Land's End in the south of England - while clad in striped pajamas and barefoot. He was accompanied by his big dog Guinness, a black Labrador, who wore suede booties.
Another time, he volunteered to spend six months in a cage in London's Regent's Park Zoo as a human exhibit to help raise funds for the preservation of the giant panda. The zoo, "foolishly," he said, turned him down. About a decade ago, he started living in caves in remote sections of the Scottish coast, subsisting on brown rice, mushrooms, onions, leeks and carrots, topped with shredded cheddar cheese.
"When I'm shut in the cave, I feel as if I'm one with the boulders, like a grain of sand - I'm part of it, in harmony with nature," he explained. "I don't want to achieve much, except in the realm of self-realization. Some people haven't got sense to stop and think that the most important thing is to stop and think. What's the point of being in a hurry to be 75 years old?"
He set about building a fire from bits of driftwood washed ashore and wooden boxes tossed over the cliffs by locals, who use the area as a dump. ''They've never been anywhere ugly, so they don't appreciate it," he said. He fanned the fire. "Thank you for the warmth, oh fire," he said.
Lately, he has been venturing out from the cave more frequently. He has gotten married, for a third time, to a woman he met while in training for one of his marathon walks.
"My wife, Pam, is a meat eater, lamb chops, that sort of thing. She's a completely normal girl. She likes to sit in front of the telly. She took a chance on a very odd guy," he said.
The couple courted by mail; Slater had a bit of a problem inviting her over to his place.
She still refuses to come near the cave. "Oh, I wouldn't live in a cave," she said. "I won't even climb down there, I don't have a head for heights." She lives instead in a 100-year-old cottage that the couple bought cheaply and refurbished, adding two apartments for tourists. She has a steady job keeping records at a doctors' office, and he now has a thriving summer business operating a tour company called Driftwood Holidays. He made his dog Tiny, a huge Newfoundland, a director.
One day in the not-too-distant future, he acknowledged, he will no longer be limber enough to negotiate the steep path to his cave. So he is converting the long, narrow attic above one of the tourist apartments into an ''artificial cave," with a spectacular view of the Atlantic and the rugged coastal islands. "When I'm too old," he said, "I'll crawl into it."
While Slater wants to be in harmony with the world, Ward, who lives in the Northamptonshire city of Higham Ferrers, likes to laugh at it, and himself. ''A lot of people take things too seriously," he said. "That's why we have a lot of psychiatrists running around loose.
"My only ambition is to go to the original throwaway nation, America. Hang Disneyland, I'd go around to the tips (dumps). . . . I'm a junkist. I see things, shapes - objects put together in different ways. I see assembling this junk as a challenge. Making something out of all these silly bits and pieces."
When he wanted to go boating, he simply built one "from three old baths (bathtubs). I got a length of pipe and welded them together, put an outboard motor in the middle and down the river we went. It cost me three quid (about $5) and lasted six years."
Next, he built a "concept car" from bits of old cars, washing machines, ironing boards and Coke bottles. Powered by a motor from a small automobile, it reaches a top speed of 20 miles per hour. "It took me three years altogether, bit by bit, and it's all junk," he said.
"General Motors builds a concept car and they spend $15 million and you can't drive it and you can't buy it," he said. "Well, this is my concept car. It may be made from bloody rubbish, but it will bloody run and it's cheaper. It's a laugh, really, a giggle." His new concept car, he said, will include "the kitchen sink."
For a time, he tried his hand at regular inventing, including a device to prevent electrical fires in automobiles, but "nobody was interested," so he
concentrated on his whimsical inventions, such as a "safety net" that he straps to his leg to catch errant yo-yos, and shoes with flashlights in the toes for dark nights.
"Some people look at me as weird," he said, "but they come home and watch the telly and go to the pub and play darts and swill ale all night. That's weird."
Even people living such humdrum existences have a chance if they really want to go for it, said Weeks. "Anyone can become an eccentric. Eccentrics are much more than chance mutations. . . . Probably very many more people have the potential or predisposition to be eccentric than ever have the opportunity to be so," he commented.
Slater said he is living proof that Weeks is right. He was once, he noted, a boring insurance broker. Now he is a proud eccentric.
"I've converted from a budgie (parakeet) trapped in a cage to a golden eagle," he said. "I can fly where I want when I want."