Somewhere between the filet de boeuf and the truffes au chocolat, the British filmaker first spied the fish in the big round glass vase of flowers, the centerpiece of the table.

"Dennis, was this your idea -- fish in the flower bowl?" asked Simon Dring, executive producer of a film company whose board is chaired by Armand Hammer, the host at last night's dinner at the Corcoran Gallery.

Dennis -- that is, Dennis Gould, executive director of the Armand Hammer black fish: "Oh, my God."

"Optional hors d'oeuvres?" inquired Simon Dring. "They're small fish. Some of the other tables have big fat goldfish -- shows how our table rates."

It was a night of crystal, masterpieces from the Armand Hammer Collection, which opens to the public Saturday, and a guest list full of big fish.

There was the National Gallery's Carter Brown, the Museum of African Art's Warren Robbinns, the Symphony's/Corcoran's/Washington Oper's David Lloyd Kreeger.(board member to them all).

Plus there were some other like Secretary of Labor Ray Marshall, Middle East negotiator Sol Linowitz ("I'm smart enough to avoid going to the Middle East if I can go to a nice dinner party", Supreme Court Justice Byron White, and assorted members of Congress and ambassadors.

And of course, 82-year-old multimillionaire Armand Hammer, who is lending this exhibit to the Corcoran, And -- as usual -- he was being paid homage to. t"Marvelous," "generous," an "angel," etc. For the Corcoran he is practically all those things, since he gave them enough money to make admission free to the museum and to renovate the auditorium. Today he'll be back in New York hostng a dinner for Pakistani President Zia-UI-Haq. He's also trying, on his own, to negotiate the Russians -- with whom he has a long and close relationship -- out of Afghanistan. Hasn't made it yet.

"He's a nice kid," said Joseph Hirshhorn, winding his way through an unusually large Corcoran dinner crowd of 550 (their count). "I've known him 212 years." And, looking around: "I've got to find Mrs. H." He reappeared moments later with her. "Found her. I though she'd left me."

"For the Corcoran to get an angel like Dr. Hammer . . . " said Clement Conger, curator of the White House and the State Department, trailling off. "There's nothing he can't do. He's got the money from Occidental."

"He's one of the few real collectors," said painter Jamie Wyeth. "Most big collectors wouldn't know a painting if they fell through it." Wyeth is not in Hammer's collection as far as he knows. "Everybody in his collection is dead," said Wyeth. "I'm not quite dead."

Noted Hammer's brother Victor (3 1/2 years younger and in from Palm Beach), "I'm a qualified connoisseur. He asks my advice. He doesn't always take it. He wants a Vermeer now." The Hammers are a close family. "There was a time when we all had a joint checking account," said Victor.

But yesterday morning, there were about a dozen demonstrators outside the Corcoran who was not quite as admiring of Hammer. They represented different environmental concerns who were protesting Hammer's Occidental Petroleum Corp. (currently being sued for damages in the Love Canal case by the State of New York.) "One of the crosses you have to bear when you're head of a public company," said Hammer duing an earlier press preview of the collection. Hammer did not talk to the demonstrators but did answer reporters' questions.

"Armand gave a pretty good defense, didn't he?" chuckled John Walker, former director of the National Gallery, who in the course of the day was called mentor by both Armand Hammer and local D.C. Commission on the Arts chairman Peggy Cooper. "I guess he had to prepare when he saw those characters outside." Everyone was swearing by Walker last night -- as in, "when John Walker talks, people listen. . .'"

"Actually, we're not different enough," replied Carter Brown ruefully when asked how he was different from his predecessor Walker.

The dinner dragged on past 10 p.m. with David Kreeger giveing a 15 minute talk on -- among other things -- the history of the Corcoran. Guest looked bored, some drank their champagne before the toast, and one congressman -- worn out by the final marathons of this Congree -- nodded off in his chair. "I hope he doesn't fall out," his wife whispered, chuckling. "It's a pretty hard floor."

So when Armand Hammer finally made a big announcement -- that he was giving his collection of Daumier sculpture to the Corcoran -- some guest had gone home and the rest still hadn't toured the Hammer exhibit. In fact, Kreeger was so anxiious to get them moving up there that after Hammer's announcement, Kreeger went to the mike and said rather huriedly, "Thank you, Armand, that was really a surprise -- another manifestation of your generosity. Now, if you will all proceed upstairs. . ."