Down a grassy slope from the Tomb of the Unknown Soldier at Arlington National Cemetery, in a valley of trees a short distance from where Deputy Secretary of Defense W. Paul Thayer was placing a wreath of carnations yesterday, two women and a girl stood silently before a grave, heads down, arms behind their backs.

While ceremonial guns were booming and ceremonial heels were clicking, while a nation was engaged in formal mourning on a day set aside for that purpose, the two women and the girl were quiet with their own Memorial Day memories.

By the time the formalities were over, and the hundreds of spectators had scattered, the two women and the girl had left. In addressing the crowd, Thayer had said that Memorial Day was a time to "pay tribute to over one million men and women who gave their lives in the armed forces of our land."

That's what thousands did yesterday as they came to Arlington Cemetery and the Vietnam Veterans Memorial to pay tribute and lay flowers. Thousands more biked, jogged, picnicked and played on a holiday from work.

Still others spent much of the day in long, often slow, lines of traffic as they made their way back from the Atlantic Coast beaches. Westbound traffic was backed up for as much as 14 miles yesterday on Rte. 50 in Maryland as motorists waited to cross the Kent Narrows bridge, according to state police.

The delay appeared to reach a peak about an hour after the bridge was opened at 1 p.m. to permit passage of boats, police said. After the 1 p.m. opening, the bridge remained shut until 8 p.m. under a new schedule put into effect this weekend to ease the traditional bottleneck there.

A state police dispatcher described the 14-mile backup as typical for a holiday weekend.

By 7 p.m., police said, the line of westbound traffic stretched for about 10 miles.

Elsewhere, even at the Chesapeake Bay Bridge, traffic was reported flowing smoothly. Although traffic was heavy, there were no delays, a bridge police officer said last night.

In Northern Virginia, state police reported "no problems at all" yesterday evening. Earlier in the day, a dispatcher said, traffic had been moderate, but by evening it had "thinned out quite a bit."

It was a gray and sometimes wet day when people eyed the sky and played it by ear. Tourists carried umbrellas along with their cameras; people wore raincoats over their jogging shorts, and only a few blue paddle boats dotted the Tidal Basin bordering the Jefferson Memorial. The rugby players continued their game as scheduled across the street from the Bureau of Engraving and Printing, but along Hains Point, the usual Memorial Day smell of smoldering charcoal was conspiciously absent.

The weather didn't stop the 39th Annual Memorial Day Parade in Rockville. About 2,000 people lined North Washington Street, according to the police, undaunted by the rain that fell during the last half hour of the clown-studded event.

Nor did the rain stop the sixth annual Alexandria Recreation Department's jazz concert.

Several hundred people sat on lawn chairs on the cobblestone court yard and around the fountain in front of the Alexandria Courthouse to hear a little vintage swing music.

Not that precautions weren't made. Karen Miller, 23, and Ellen Morace, 22, both college students and residents of Alexandria, brought raincoats to wear, a sleeping bag to sit on, and plenty of plastic to keep their lunch of bread, cheese and apples dry.

"We thought it might rain, but we came anyway," Miller said. "We just parked really close so we could make a dash for the car if it started to come down hard."

Alexandria's King Street was awash with tourists and natives strolling babies, eating ice cream, holding hands and window shopping. For some, coming to Old Town was a sort of compromise with the questionable weather.

At the Fish Market restaurant, Rusty Hanesborough, Lisa Sedinger, and Billy and Carolyn Voegtli were pouring down extra large schooners of beer.

"We wanted to sit out in the sun, but there wasn't any. We wanted to go fishing, but the rain made the water too muddy," said Carolyn Voegtli, 21, from Vienna.

During yesterday's ceremonies at Arlington Cemetery, Deputy Defense Secretary Thayer dedicated a plaque that will be displayed on a marble pedestal near the Tomb of the Unknown Soldier.

It reads:

"The crypt for the unknown serviceman from the Vietnam War lies empty as the nation continues to identify those American dead who have been recovered from Southeast Asia. In the meantime, there is nothing more important to the soul of our nation than that Americans never forget the sacrifice of those who died for freedom in the Vietnam War."