Acting Gov. Blair Lee III recalled yesterday how his great-great-grandfather had to spend a full day on horse back to get from his residence in downtown Washington, the Blair House, to his summer home in Silver Spring.

Yesterday, standing near the futuristic new Metro station a half mile from his boyhood home in Silver Spring, Lee and other area politicians inagurated the stretch of Metro rail which will cut that trip to about 17 minutes beginning Monday, linking Maryland, Virginia and Washington for the first time.

An estimated 35,000 people helped celebrate the opening of the Silver Spring extension to the Red Line by taking free rides back and forth between the four new stations - Silver Spring, Brookland, Takoma and Fort Totten.

Bands played pennants waved, and kids took off from school for the occasion: the high-spirited fun before things get serious next week.

"I'm very pleased to be standing on a Prince George's-owned platform, waving a Montgomery County flag, sitting beside the mayor of Washington and with representative from Virginia," said Sen. Paul S. Sarbanes (D-Md.)

At Brookland, the first stop on the ceremonial tour, Angela Rooney declared to triumphant cheers that "we, the citizens of Brookland, stand on the land saved from destruction from the now-defunct Northeast Freeway."

"They said it would be a cold day when Metro came to Maryland, and it is, "joked Rep. Newton I. Steers Jr. (R-Md.) during outdoor ceremonies in Silver Spring.

The crowd of 500 residents and dignitaries, catching the drift of his jab at the regional feuds that occasionally threaten Metro's future, laughed and stomped their feet to thaw their toes.

"You know, I felt like they must have felt back in the 1800s when they hammered the last peg linking eastern and western U.S. by railroad," said Del. Lucille Maurer (D-Montgomery) afterwards.

"This is much better than the New York subways," said John Marsh, a Silver Spring banker who rode the train yesterday. "For one thing, you can't write graffitti on the ceilings" of the cavernous Metro stations.

"I think it's fine," said Floreencio Sandaval. "It's almost as good as the one in Munich."

And Montreal and Toronto, added Ivy Fraser of Silver Spring.

"I just like all kinds of trains," Evelyn Sandaval commented. "Subway trains especially. I always feel like I'm going somewhere." Lark of Children

A gaggle of pupils from St. Joseph's Day Care Center is Silver Spring clung to their teachers who acurried them from train to train. "This is the first ime many of them have ever ridden a train," one teacher remarked.

They rushed in and out of the doors, poking each other with Metro pennant sticks. Teachers wiped runny noses that their charges pressed against train windows.

"Is it fast?" 10-year-old Michael Currie asked his classmate Joe Heutte of St. Anthony's Catholic School.

"It's pretty smooth . . ." Heutte replied. Some Have Complaints

"The windows are already dirty," one rider complained.

"How come all these kids ain't in school?" another griped.

The New York system is better, said Steven Jacob, a 17-year-old Montgomery Blair High School student. "It has graffiti."

"To me, Metro has no value whatsoever," said Nathaniel Greenburg, a Silver Spring chemist. he rode the train anyway. Compliments Numerous

"This is the only way to travel," said Albert Bacon, a Silver Spring dentist as he took pictures at the Brookland station.

"Can you imagine driving in traffic along Georgia Avenue in seven minutes? You'd have to have wings," another rider told her friend.

Ray Vondran was giddy about it all "I think this is fantastic!" he shouted at a Metro operator. "Metro is the best thing that ever happened to me."

"I have a big gas-guzzling Oldsmobile sitting at home, and I'm going to leave it right there," said Vondran, a Silver Spring resident who teaches at Catholic University in the District. "I'm from New York and used to good train service, but this is the best ever I'm tickled pink." Train Enthusiasts

"Buses are depressing. There's a lack of courtsey. You're lucky to get a civil word from the driver. The buses are cramped and you can't sit down. I've never had that experience on Metro. I associate trains with fun."

Chandler Hottel, who has ridden trains to Harpers Ferry and Mexico City, waxed approvingly about the subway. "We've been watching it being built almost as long as we've been living in Silver Spring," his wife, Catherine, said. Mayor Arrives by Car

"Mr. Mayor, I'm sorry you didn't use public transportation to get here today," a flag-waving Brookland resident told District of Columbia Mayor Walter Washington. Washington arrived at the first station - Brookland Catholic University - in his black limosine.

"He (the mayor) has got his own transportation," muttered one Metro official to another as they rode by subway to the Brookland ceremony.

"How do you interpret that?" one asked the other.

"I don't know."

The mayor journeyed the rest of the trip by train. The Newness of It All

A woman who has lived in Takoma Park for 48 years ventured out for a free ride. As the train pulled into the next stop, only three minutes from her community, she looked up. "This is Fort Totten? Never heard of it."

She wasn't alone. Later in the day, a mellow voice over the subway's public-address system announced firmly: "The next stop is . . ." He stopped. "The next stop is . . . uh . . . uh . . . uh . . . oh, oh . ."

The riders hushed. The train operator tried again. "The next stop is - Fort Totten!" and they gave him a consoling cheer.

They blessed the trains the stations, each bolt spike and rail; the dreamers, the planners, the operators and even the politicians.

A Catholic offered the Lord's prayer; a rabbi, the Mizpah Benediction. And when a priest asked for heavenly "benign solicitude" on all Metro riders, a couple of skittish travelers winked at each other in relief. And when it is all said and sone a priest asked in one supplication, "watch over this system all the time with thy benign solicitude," so that those who ride the train may arrive safely at the next station as well as their divine reward. One Aid Fan

Richard Reams rose at 5:30 a.m., yesterday for his free journey. A deaf mute, Reams "just lives for Metro," his mother said Reams stared out the window, holding the notebook and pen he uses to communicate with others.

Reams has ridden every Metro line as it opened. Once he made his mother wait four hours at the Mayflower Hotel for the opening rides on the very first Metro route.

From the first time there were things in the newspapers about Metro, he'd cut out all of the articles. He has to get excitement out of something," she said. Last Minute Decision

Murray Wolf was on his way home from work last night when he heard on his radio that the free rides would last until 6 p.m. He hurried to Silver Spring, picked up his three children, his wife and her parents and headed to the nearest subway stop.

"I turned off my brisket, I turned off my potatoes, I turned off my carrots to come here" Elaine Wolf said after her ride. "But I'm glad I did. I've been looking forward to this for a number of years. I'll take it down town shopping."

Also contributing to this story were Washington Post staff writer Caria Hall, Barbara Katz, Paul Valentime and Vernon C. Thompson .