It stopped being a hike long ago.

He started the week Carter was inaugurated, and Carter has come and gone, and there's still two more years to walk.

Sometimes it seems like a seven-year prison sentence, he says. His friends who were in college have now finished graduate school. He himself got married and has two children. He has become a different person.

And still he walks.

"I think there's something in every human being that has to try and go the limit," says George Meegan. Then, characteristically, he undercuts himself. "Actually, it would take a formidable courage to stop."

Meegan, 28, is walking from the tip of South America to Prudhoe Bay, the northern most coast of Alaska. He figures it is 18,500 miles. He has done 12,504 so far, in 1,558 days. He measures by mile posts and road maps and his own regular pacing. It is no race. He stops during the rainy seasons, once paused for half a year to write a book. It took him 13 months just to get through Argentina.

"This extends the frontiers in a very humble way, I think. I'm the second man to walk through South America but the first to do all of Latin America, the first to walk from Capricorn to Cancer, the first to walk 90 degrees of latitude."

He is not interested in records any more, but they accumulate anyway.He has written a 187,000-word book and started another. He has slept in $50 motel rooms free, rooms so big his tent would fit on top of just one of the beds (and be so poor he was living on nuts). He has slept in $2 Central American flea pits, in police stations, in jails, in restaurant back rooms, in derelict cinemas, in churches, in Indian huts, amid the vomit of strangers, in a giant iron pot and a NASA tracking station. He sleeps anywhere he can get out of sight. He stops at nightfall, lights his candle, opens his Michener's "Centennial" ("my best friend") and that's his camp.

At Lake Titicaca it was so cold he was awake all night shivering in his sleeping bag and dozed off when the sun came up. "I became a sun worshipper, like the Incas," he says.

He doesn't bother with fires or hot food. Washing dishes is too much trouble. There's not always water.

"Sometimes I've licked the dew off leaves for a little moisture. It's not much fun. The bugs get there first."

He ate bread mostly.Bread and onions.

Once he ate an iguana. It wasn't so bad.

Pulling behind him his 11-pound steel luggage dolly, built for him by some shipyard friends for a case of beer and a bottle of whiskey, he would come into some remote South American village, picking up a tail of ragged children. He speaks fluent street Spanish, by the way. When he started he knew nothing more than "por favor ."

"People weren't intimidated by me. I wasn't like some huge character with a pack on his back nine feet high and a big knife. I had my hat and my cart. Never mind your trousers, it's your hat that's important."

The chin string is as frazzled as an old snakeskin.

He has worn out seven pairs of hiking boots.The heel linings go first.

Striding along at precisely six kilometers an hour, a mile every 16 minutes, he has been averaging 25 miles a day but expects to do better on the good roads of North America. Once in Peru he walked steadily uphill for 2 1/2 days, then downhill for 2 1/2 days.

In the United States he has found the deeply set-back houses with their front yards a special hazard. "People see you coming up the walk and they come out to meet you with a gun sometimes. You feel so exposed. It's hard even to ask directions after dark."

In fact he plans to cross North America through Canada, diagonally, because he feels it is a less violent country. He made that decision after the John Lennon shooting.

"It's impossible to hike any distance with a partner, even your best friend.

The pace is so important, and you want to stop when you want to stop."

He also hates any walking that doesn't count on the trip. He figures he has trudged many miles around various cities trying to get visas stamped, resenting every step.

Walking alone has its problems. He has been shot at, threatened with a variety of weapons, set upon by Panama City street gangs, robbed more than once. He had trouble with his stomach, caught a gum disease (the bread diet, no doubt), once started urinating blood -- a frightening discovery when you're in a strange country miles from anyone. In Honduras he felt himself cracking up: couldn't eat, couldn't sleep, feared the end of each day "because I had nothing left to look forward to except being with me," dreaded the sleazy little villages sunk in dirt and poverty and their sullen inhabitants, reckless with despair.

That time he cured himself by plunging into the thing that was bringing on his nervous breakdown: He got back on the road, hiked until his morale was restored.

"You don't get ill if your morale is high. When you're alone, preventive medicine is knowing you're not going to get help."

About the shooting. He was crossing a river in Panama in a canoe when he heard shots. "Excuse me," he saked his companion, "is someone shooting birds?" The man replied, just before diving into the river, "No, boss, it's the patrol. They shoot twice to warn and then to kill." It turned out they thought he was carrying drugs. It was in fact 25 cans of Planter's peanuts. He parted friends with the patrollers. They even gave him a haircut, and for two months afterwards people asked him, "My God, where'd you get the haircut?"

He set out with his life savings of $11,000, had spent it by Guatemala, mostly in air fares for his wife, Yoshiko, whom he twice sent home to Japan to have their children. His brother gave him the money to get to Texas. After that he decided to depend on what fortune brought.

"It's a strain," he says, "but it's working. The reason I've survived is good will. It's so marvelous, a kind of providence has protected me. It's made a Christian out of me. It takes a kind of faith." He laughs with embarrassment.

When he was down to his last $100 he met a fellow Englishman who gave him $20 unasked. He never asks for money. The man who hired the Beatles (in another lifetime . . .) for $10 a head to play in Liverpool's Cavern Club gave him $100. A motel maid left $1 in his scrapbook. An 80-year-old woman living in the most abject poverty in a filthy Panama City slum mailed him a dollar. A black man he met gave him 25 cents and apologized for not giving more.

Reaching Nicaragua just after Somoza's defeat, he found the towns covered with red and black Sandinista banners like some medieval fair day. In Alabama police arrested him for urinating by the highway ("What yo' doin' boy?") but wound up giving him the warrant for a souvenir and supplying him with an orange safety vest, which he still has.

In Plains, Ga., he met Jimmy Carter, had his picture taken by Chip. In Washington he is spending several weeks with the William Halls. He met their nephew in Bolivia, remembered something about relatives here when he was in Richmond, phoned the friend collect in Aspen and got the aunt and uncle's address.

Who is George Meegan anyway, and why this madness?

He's from Kent, England. He has raggedly cut blond hair and a mustache a slight, hard-muscled body. He's a dreamer who lives his dreams. At 16 he quit school to go to sea, sailed in tramps for seven years winding up a second officer. (Coming into port was always an event then. But on foot, dragging his cart, miserably searching for a place to flop, a bite to eat, he hated ports.) He left home the morning of Jan. 31, 1976, in a light drizzle as his mother waved goodbye. He didn't see her again for four years: in a reunion at Brownsville, Tex., which also included his brother, and Yoshiko, and their daughter Ayumi (which means "walk") and their infant son Geoffrey Suzumu ("keep going"), conceived when his wife stayed with him during a five-month pause at Panama City.

He had met Yoshiko in Japan in his sailing days. She flew to join him in England just before the great journey, caught up with him in Buenos Aires, where he landed in a Pakistani tramp under a Maltese flag, and accompanied him to the starting point, Ushuaia, the southernmost town on earth. He had fixed her up with her own cart.

"We walked 300 yards that first day," he says. "She never realized it was to be walking. She thought it would be some sort of bus trip."

She followed him by bus through Argentina. They were married in the police station at Mendoza, and when the baby came due he sent her home. "I've known my wife six years and only lived with her a year and four months. Those were the happiest times. She's been so understanding. She knows I have to do this."

It started as a walk. It has become, he says, a celebration of freedom. "It has become a tribute to the thousands and thousands of people who helped me. And when I'm done I plan to live in Japan -- as a thank-you to Yoshiko -- and write. I want to write another book, about my seven years at sea. Now that . . . that's a real story!"