There were 12 violinists, more than one thousand guests, and as many orchids and bottles of Halston Night perfume at the Corcoran Museum of Art's annual fund-raising ball last Friday.

There were lots of diginitaries, and no one was more sought after than Sheik Faisal Alhegelan, the ambassador of Saudi Arabia. He stood near a pillar with Heart columnist John Wallach, who was bending his ear about the AWACS decision. "Absolutley, absolutely," the ambassador nodded.

"I told him the time has come to decide whether the Saudis are allies or enemies," said Wallach. "He said to me that if there is no peace in the Middle East by 1985, there will be no Middle East."

"Oh, no," said the ambassador after Wallach had moved away. "I was misquoted." The outcry of Israel "will pass. It is just to milk something more." From the United States?

"Yes," said the ambassador. The Leak Principle

In the center of the rotunda of the National Academey of Sciences there is a large glassy orb, filled with water. Last Sunday, at the Academy's garden party, the orb was leaking, and scientists, this provoked no end of interest.

Frank Press, once Jimmy Carter's science adviser, was very much in evidence, shaking hands and taking congratualtions as incoming president of the academy.

"how can you speak on so many subjects?" VI Keilis Borok wanted to know. He is a Soviet mathematical geophysicist, and one of the 12 foreign scientists the academy elects to its rools each year.

Before Press could answer, someone else did, quoting Oscar Wilde, who once bragged that he could speak on any subject. "What about the queen?" came the query. "The queen is not a subject," said Wilde.

But back to the leaking orb. "The scientists were all standing around watching it leak," said journalist Daniel Schoor. "They kept saying things like 'the eccentricity of motion' and so on. What a way to talk!" Schoor exploded. "I told them, you guys are the ony ones who can turn a mistake into a principle."

According to lawyer Adam Yarmolinsky, outgoing academy president Philip Handler watched the water flowing onto the floor with such calm that many bystanders thought the orb was supposed to be leaking. "Perfect calm," said Schoor, "just like he handled the Einstein statue out front." With Friends Like These . . .

Art Buchwald got roasted last Saturday night. By his friends, of course, although they were, by their own admission, just merciless.

And the roasters were: Lawyer Joesph Califano, columnist Philip Geyelin, AFI impressrio George Stevens Jr. and film lobbyist Jack Valenti, literary agent Irving Lazar and television cirtic John Corcoran. They waxed witty for a benefit sponsored by the Northern Virginia chapter of the American Heart Association.

"You all know Art's an author," said Corcoran, "But you probably never heard about his book. It's called 'Dewey, the Admiral, the Decimal, the Duck.'"

"To be roasted by one's peers is the highest honor," Buchwald intoned, "Only in America would the leading speakers of this country get together to beat the hell out of the son of a poor Jewish immigrant.

"It's not easy for me to thank the speakers of this evening. I guess most of you are still wondering who the hell they are." Califano was introduced as "Joe Califano, an architect of the Great Society, which made it so easy for Ronald Reagan to win the last election to easily."

"I want to thank my friends," said Buchwald, "for coming tonight and giving up -- what movie was on tonight?

"I haven't enjoyed anything this much since I watched Agronsky and company last week." Funds for the Enfant Terrible

For a man $200,000 in debt, Rep. John LeBoutiller (R-N.Y.), a.k.a. the enfant terrible of the 97th Congress, was positively ebullient at his fund-raiser at the Fairfax Hotel Wednesday night.

He had lots of nice things to say about his cousin Gloria Vanderbilt. "She has never voted for a Republican before Ronald Reagan, you know," said the congressman. "But she said she'd campaign for me, and do commercials. And my sister was thinking of something like John Boutiller for Congress jeans."

Lawyer Steve Martindale was also in attendance, and as it happened, he'd had dinner with Gloria just the night before, at her new place at 10 Gracie Square. "It's to die for," said Martindale of the jean queen's new digs.

LeBoutiller wrote a book called "Harvard Hates America," and says he's considering a similar book on the campaign experience. And in the meantime, never one to rest, he's got another book idea. The title? "How to Take over the Soviet Union without Firing a Single Shot."