LONDON -- They are forever ridiculed. Comedians tell jokes about them. They are mocked in the tabloids. They are the train spotters. They care about British trains. Some of them, it is said, care about little else.
But of all Britons, they would be the first to offer a riposte to French President Francois Mitterrand's disparaging comparison this month between French and British trains -- if they had one.
Mr. Mitterrand was in Lille opening a new service from Paris to Calais, a train that travels more than 200 miles an hour. When the channel tunnel opens next year, he said, passengers from Paris "will race at great pace across the plains of northern France, race through the tunnel on a fast track and then be able to daydream at very low speed" all the way to London.
He was right. That's what stifled all rebuttal. Britain's high-speed link won't be ready until 2000. No train in Britain today can go 200 miles an hour. Even friends of the British rail system, a shrinking population, see it as lackadaisical, even pokey, awaiting its own Mussolini to make it right.
British trains are occasionally stopped by such events as snow or leaves on the tracks, prompting some to inquire whether leaves exist in France, or at least leaves as formidable as English leaves.
Still, the train spotters love these trains. You see them on the platforms of stations from Edinburgh to Penzance, from Ipswich to Flint and at all the stations in between. They stand alone or in small groups, hour after hour, huddled against the cold and wet in their parkas, called anoraks.
They have notebooks. They jot the identifying numbers of the locomotives as they arrive to the station. They jot the numbers of the passenger cars, the numbers of the freight cars. They do the same with trains passing through.
Line upon line is filled, and when the notebooks are complete, they start new ones. Some take pictures of the trains. Some videotape them.
Books are published for these people, train spotters' guides. They list the numbers of the thousands of pieces of rolling stock British Rail owns.
"Some people take it as a challenge to see every wagon [freight car], every coach [passenger car] in the country," observes Steve Knight, the news editor of Rail Magazine. He regards this as a healthy ambition, broadening.
"It involves travel. That's good."
Why do they do this? Few non-practitioners have been able to find an answer to that, or to discern the appeal of this most peculiar pastime.
"The term 'train spotter' was coined by the tabloid press as a totally eccentric hobby," says Mr. Knight. "They think people who stand at the edge of rail platforms with notebooks are idiots. We consider it no more eccentric than knocking a ball in a hole, then taking it out again, or dangling a worm in the water."
Not everybody is swayed by this reasoning. A young female telephone operator at British Rail volunteered: "We call them GANGYs."
"Green Anorak, No Girlfriend Yet."
Malcolm Parsons, a British Rail spokesman, is more sympathetic: "Our policy is that as long as they behave responsibly, they get access to the platforms."
Train spotters first appeared in Britain after World War II. They have formed clubs. They compare notebooks. They go on group holidays abroad to look at other countries' trains.
In 1970, two were arrested as spies in Poland for doing what comes naturally to train spotters at Zagan railway station. But they were released as harmless and arrived home heroes, at least to other train spotters.
The British, as everybody knows, are avid hobbyists. They keep bees, collect stamps, cultivate all sorts of recreations to help kill time until time returns the favor. Train spotting, which at least puts its devotees out in the open air, may not be the oddest.
Gerald Kaufman, the Labor MP and former shadow foreign secretary, collects American musical comedies. He has been described in the public print as an "expert" on the splash dance in "Singing in the Rain."
Nobody knows how many train spotters there are in Britain. Peter Fox, director of Platform Five, which publishes train spotters' guides, won't say how many he sells. It's a trade secret.
He's kind of a retired train spotter himself. "I don't spend much time doing it these days," he says. "But if I see one I haven't seen before, I still write it down."
Mr. Fox insists it has a very primal appeal that's not really appreciated by those who haven't felt its pull. "There are closet train spotters," he says. "Businessmen, commuters. I've seen them; when a train comes in, they'll write its number down."