Some of them remember what it was like when everybody took the train, when the Twentieth Century and the Lakeshore Limited and the Champion and the City of San Francisco were names to quicken the blood, when Grand Central Station conjured up all the glamor and excitement of going places.

Some remember the sights and sounds, the deafening hiss of steam billowing in a firecracker-smelling white cloud as you strode down the platform, the peculiar bawling of the conductor -- "Bo-o-a-a-r-r-d!" -- and the baying whistle and the clicketyclacks that were so much a part of our lives that at least one comedian made a career out of imitating them.

And some had never taken a train before but remember standing and waving in their backyards when they were kids and the big through-train to Chicago roared past.

In any case, they're all here 1,700 of them, for the annual convention of the National Railway Historical Society, and for days they've been crowding aboard every train in sight; by steam to Front Royal, by disel to Harper's Ferry, by Amtrak electric through the Susquehanna Valley, and also by boat around Annapolis harbor.

Since many of the society's 10,000 members are trolley nuts, history nuts, old-railway-station nuts, photography nuts, model-train nuts and hopelessly addicted sightseers, groups are visiting various train and trolley museums in the area.

The convention ends tomorrow with a ride behind Old 4935, the electric locomotive designed by Raymond Loewy and recently restored, to the delight of the venerable Loewy, who helped create the look of American in the '40s.

You didn't have to be around in the '40s to appreciate trains, but it helped. Many members are retirees like vice president George S. Hartman, who got the bug nine years ago through he still doesn't call himself a train buff.

Many saw the great extravaganza of rail history at the 1939 New York World's Fair, where famous trains chugged on and off a giant stage, forming the sturdy spine of a somewhat breathless pageant.

Many still talk about how it was, taking long trips during World War II, when the hard green plus seats were asprawl with dozing serviceman and every car had its quota of keening babies and soldiers' wives, and there was always a drunk in the washroom and a smell you could never forget: stale sandwiches, cigarette smoke, cigar smoke, train smoke, vomit and the special acrid, municipal-green smell of the train itself, a smell of anxiety, sweat and far places.

It was a way of life, the train, just as the highway is today. It was where you learned to sleep sitting up (and woke with a round smudge where your forehead had rested against the cool window) and to accept a power greater even that your parents. (One night the Minuteman was shunted aside east of Utica for five solid hours while 44-- count 'em, 44-- entire trains hurtled by, packed with soldiers. It was two weeks before D-Day.)

"A lot of our people are parents who want their children to experience something they've maybe only seen on TV," said Hartman. "Some of the parents, themselves, had this from their parents in turn . . . "

(Did you ever take the Vista-Dome from California with three small children in a pair of roomettes opened up to create one slightly larger and even more squalid roomette? With a suitcase full of peanut butter and Triscuits and grapefruit juice and various things that crumbled and smeared and scattered into the carpet? But what you got for it was gawking up at the Rockies through the glass roof and staring straight, for one instant, into the face of an actual cowboy as he sat on his pinto not 10 feet from you and waited for the train to pass.)

There's something else at the convention: private railway cars. A half-dozen were parked at Union Station, having carried fans here from all over the country. One tour group, from Cincinnati, is living aboard during its stay, and next week they'll go on to New York, hitching a ride with Amtrak. There are 16 roomettes and four bedrooms. All filled, said entrepreneur Joe Kidd, and three day passengers too.

"Private cars are a big thing now," he said. "More and more people are buying them up and restoring them. It's getting bigger every year."

Do you think . . . ? Is it possible . . . ? Could they be coming back . . . ?