There were times, yesterday afternoon, as the ice made its stately march down the Potomac River, when it seemed to be scene for several quite different dramas.

[LINES ILLEGIBLE] arrest if they set foot on Chain Bridge or parked along the George Washington Parkway to gaze down at the Potomac. From Georgetown to Caoin John. helicopter blades whirred, and bullhorns barked amplified warnings to the curious.

Meanwhile, to those for whom the ice provided the prefect excuse for a winter carnival on a Saturday afternoon. "It looked like a marshmallow parade" as one young girl declared from the vantage point of her father's shoulders, as they stood on a scenic overlook of the George Washington Parkway above Key Bridge.

For the bravemen of the Ball-Ilca-Icy-Granite Construction Company, the ice meant wilted orchids. When not fighting ice floes from a crane perching on the roadway of Chain Bridge explained master machainic Steve Beach, who is known as "Dallas" to his friends, the men work on a subway crew that had just completed a tunnel underneath Connecti-cut Avenue near Yuma Street NW.

In honor of the tunnel's completion, their construction company had scheduled an elegant "holding through" dinner dance for the men and their wives at the Shoreham Americana Hotel. But now the orchid corsages, picked out just a few hours earlier, lay abandoned on the dashboards of crane cabs and pickup trucks.

"My wife isn't going to like this," said welder Ray Burroughs, as the big cranes trundled over Chain Bridge. "She's not gonna understand this. I don't understand this. The only ice I've ever broken is at parties."

For many people yesterday, the ice was the party. Cars stopped at random along the parkways. MacArthur Boulevard, the Whitehurst Freeway and just about any other street near enough to the river to gawk, snap pictures and draw glares from any nearby police officers.

"We don't know what's going to happen," said one U.S. Park Police officer. "We just want people out of there. It isn't safe. They many think it is, but it isn't."

Few places offered a better view of the ice parade and the chaos it could cause than Roosevelt Island.

Located under Theodore Roosevelt Bridge opposite the Georgetown waterfront, the island nature preserve is bounded on one side by the ice-filled Potomac River and on the other by the ice-filled Potomac River.

For the dozen or so sightseers yesterday, this was both good and bad.

It was good because they had to only at the Roosevelt Island exit off the George Washington Parkway, walk over the river on a footbridge and wander along the banks of the Potomac, watching sheets of ice crash and crackle at their feet.

It was bad because that same ice threatened to crash and crackle that footbridge to smithereens which could leave the sightseers stranded, if not submerged, on Roosevelt Island.

From nowhere came a broadcast warning: "Get out of here now. This is the police. Get in your cars and leave the area at once. Your lives are in danger."

When it became clear that the warning was from a helicopter above, rather than any authority in the immediate vicinity, a feeling of loneliness and desperation set in.

"Did I hear him right?" one woman asked her boyfriend, who was holding her hand during a brisk lovers' stroll through the woods of Roosevelt Island.

The police loudspeaker boomed again: "Get in your cars and leave this area at once or you will be under water soon."

"Yeah, we heard him right," the boyfriend tried to reply calmly, while wasting no time joining a rush of people hurrying out of the woods.

Soon, flashing red lights were visible as a U. S. Park Police car stationed itself at the other side of the footbridge, declaring from its public address system that all should save themselves now.

Parents held their children's hands, leading them back across the bridge, everyone now more conscious of the huge blocks of ice beginning to cover the little footbridge.

"It's like a disaster movie," one woman said. 'Why are they making such a fuss," her friend wanted to know. But both sounded scared to death.

Just then, a block of ice rose about a yard out of the water, fell onto the bridge, and burst in half with the sound of cracking bones. A woman, trying to both watch and walk, fell down. She lay there, squirming on a sliver of icy asphalt, until the man behind her helped her to her feet. "I think we all better get out of here," she said.

"You're lucky to be standing here," a park police officer told her when she reached the other side of the foot-bridge. He had a little lecture for everyone who made it across. "Do you know how lucky you are?" he asked one man. "How would you have gotten across if the bridge had washed out?" he inquired another.

Meanwhile, at Chain Bridge, the scene was much more placid. Too placid for Dr. John Holaday of Rockville. He was sitting at home yesterday morning, he said, when his wife came back from a trip downtown to tell him the ice.

"We jumped in the car and came right down," Holaday said. "This is just the right kind of disaster. No people are going to get hurt, but some things might. I want to hear some big crunching sounds."

But there were no crunching sounds of any size at Chain Bridge. So Holaday was off to the Kennedy Center. "We hear there's more ice there," he said.

"It's something to do," said Don Champion who, with his bride of one day, Kathleen, was also on the ice hunt. "Now that the football season's over, weekends can get kind of boring."