Whistling, stomping their feet, clapping their hands, waving towels and pennants and brooms from the kitchen pantry, maybe 50,000 people stood in a ballyard at dusk today and called in one voice, "We want the O's . . . We want the O's."

The Orioles lost today, 10-2. They lost to Milwaukee in a game for the American League East championship. They had won four straight games when a single defeat meant the end. But now in the dusk, they had lost the season's last game without ever being close in it.

And the 50,000 faithful, wanting their Orioles for a curtain call so they could thank them properly, saw a little fellow wearing No. 4 pop up the dugout steps. Earl Weaver, the manager, is No. 4 in your program, No. 1 in Baltimore's heart. Only 52 but (he says) worn out by 35 years in baseball, he's retiring now (for how long no one knows). Over 14 seasons, the wizened gnome/genius made the Orioles big winners, and this was his last game.

"Weaver 4 President," a banner said.

"Thanks, Earl," another said.

His baseball cap in his left hand, his right hand held high in thanks, Weaver stood 30 feet in front of the Orioles' dugout. He lifted his face to the upper deck. He turned to the right field seats. He blew kisses around the ballyard.

Then he let his hands fall to his hips, as if the moment was too much to handle, before calling out beside him a few of the Orioles. The Orioles' self-appointed cheerleader, Wild Bill Hagy, twirled his cowboy hat over Weaver's head, calling down more thunder from the 50,000, and then in his contortionistic way used his body to prompt the customers into spelling out, "W-E-A-V-E-R."

Weaver disappeared into the dugout at 6:26 p.m.

They played "Auld Lang Syne" at 6:33.

But at 6:42, here came Weaver back onto the field, now in a sweat shirt, now blowing two-handed kisses to the faithful.

And record this: the last, delightful thing Earl Weaver did on the field on his last day as Baltimore's manager was, laughing all the while, twist his body into Hagy-esque shapes to lead the 50,000 in chanting, "O-R-I-O-L-E-S."

What a day it had been in Memorial Stadium, where a week ago such a day of promise seemed too much to ask even of the most generous gods of ball. Then the Orioles had lost two straight at dumpy Detroit to fall four games behind Milwaukee with only five games to play. A season-ending four-game series with Milwaukee seemed an exercise in depressing what-might-have-beens.

But the Orioles won their last game at Detroit and then the first three of this series that drew 150,760 people to the grand old ballyard on 33rd Street. So today's game would speak for the whole season, 161 games of work with one to settle it all.

The Orioles owner, Edward Bennett Williams, looked onto the empty field two hours before game time.

"I'm throwing up every four minutes," he said with a smile, adding: "You couldn't ask for a greater confluence of circumstances. We're playing the team with which we're tied. For the East championship. In beautiful weather. A packed stadium. And no pro football."

"Does that mean it's a helluva match-up?" said the Milwaukee general manager, Harry Dalton. "It's classic."

"Who's going to win, Howard?" shouted out a young man wearing a T-shirt with the legend, "In Earl We Trust."

Howard Cosell, leaving the field after batting practice, called back, "The Birds."

The opinion was widely shared, especially by those of the 50,000 who carried brooms.

"Sweep . . . Sweep . . . Sweep," chanted Orioles' loyalists at the door of the bus unloading Milwaukee players two hours before the game. "Choke . . . Choke . . . Choke." These are your basic baseball taunts directed at teams that lose every game of an important series.

"We're going to make a clean sweep," said Tom Cutter, 31, a bartender from Woodlawn, Md., who carried his broom with a five-pound bag of popcorn tied to it.

Dozens of people carried brooms. The brooms came from restaurant maintenance shops, kitchen pantries and basement closets.

"Mine was in the trash," said Wayne Rudick, 29, a mattress salesman from Baltimore who said he expected today's crowd to be "rowdy and fun."

Up in Section 35, high above right field, Scott Strohman's broom served as a standard for a sign reading, "Orioles Sweep, Brewers Weep."

Alas, 'twasn't so. Milwaukee led, 3-0, before Baltimore scored once. Only twice did the Orioles even get the tying run to bat. And when Milwaukee left fielder Ben Oglivie made a running, sliding miracle of a catch at the foul line to end Baltimore's biggest threat in the eighth inning, there came a great hush of silence over the ballyard.

Such a play by an Oriole would have caused the earth to shake from the sound. Oglivie's play seemed a piece snipped from a silent movie. Depression set in for the 50,000, a depression made profound when Milwaukee scored five times in the top of the ninth.

In the Orioles' last desperate at bat, Weaver used four pinch-hitters. He did not go gently into retirement. But it came to naught. It was over, then, and the 50,000 wanted only to see their heroes one last time, to say thanks for the memories, and when Weaver left the field for good there came over the public address system a song whose memorable verse is, "Nobody does it better."