When U.S. Attorney Peter F. Vaira heard about the trial, he sent a memo to his assistants urging them to "drop by periodically to watch what promises to be good advocacy."

When U.S. District Court Judge Louis H. Pollak had 10 minutes free on Wednesday, he went downstairs to take a look. On Friday, Assistant Philadelphia District Attorney Cliff Haines brought 14 neophytes from his office to the third-floor courtroom of the federal courthouse and told them to listen and learn.

The names of the two defendants, Dominic F. Antenelli and Joseph Yeldell, mean nothing here and the complex bribery and conspiracy cases seems to baffle onlookers. But in this city whose very name is synonymous with legal craftiness, the major attraction for those who drop in on the trial is one of the attorneys for the defense.

"I'd heard that Edward Bennett Williams was the best trial attorney in the country and that he started his trial career trying accident cases for a bus company," said Assistant U.S. Attorney Ruth Simon who, along with nearly half her office, stopped in to hear Williams' opening argument Tuesday.

"I came here to see Williams. I don't know what this case is about," said Ronald Coleman, a member of the strike force team in the U.S. attorney's office.

For the longtime "rail-hangers," the habitual courtroom spectators here who remember the date of every great trial they have seen and tick off for any willing listener the names of the attorneys they have watched, the advent of Williams is a True Event.

"I seen 'em all," said Bob Inger, whose status as a canny rail-hanger has led Vaira to dub him an "Honorary Assistant U.S. Attorney."

"I saw Bailey [criminal attorney F. Lee Bailey] when he was here on the Osser case, I think it was in '72. But Williams is incredible. Did you see his opening? He talked for an hour and a half on a case as complex as this, and he never looked at a note."

As the court broke for lunch on Friday, Assistant District Attorney Haines leaned over the courtroom railing, introduced himself to Williams, then stepped back while his young colleagues clustered around to ask questions.

What difference does the racial composition of the jury make? asked David Churchill, who recently left a clerkship with the U.S. attorney's office in Washington. Williams responded in general terms, saying that black jurors tended to be harder on defendants in white-collar corruption cases and more sympathetic to defendants charged with street crimes.

Over at the defense table, where William's associates were gathering up their binders of trial transcripts and other legal paraphernalia, cocounsel David E. Kendall looked up with a grin and asked, "What's he (Williams) doing? Signing autographs?"

Williams' celebrity, both for his success in defending highly-publicized cases like the John Connally-milk fund case and for his renown as an owner of the Washington Redskins and the Baltimore Orioles, was clearly a major factor in drawing a steady stream of traffic in and out of the courtroom.

But Williams expressed some dissatisfaction with the situation. "It's not right," he said. "I don't like this much. This is a trial, it's not a theater."

But there were other reasons the spectators came. Some local lawyers wanted to see a former law school classmate on the prosecution or defense teams. Assistant U.S. Attorney Henry F. Schuelke III attended law school at Villanova University in the Philadelphia suburbs and his colleague Michael Lehr got his training at the University of Pennsylvania and after the trial will be joining the local firm Ballard Spahr Andrews & Ingersoll.

Other spectators were treating the trial as something of a legal clinic, and with most local judges attending a conference in Hershey, Pa., for most of the week, there was little else in the courthouse to watch.

On Wednesday, Assistant U.S. Attorney Gregory T. Magarity encouraged some third-year law students he teaches at nearby Temple University to spend some time studying the legal techniques used by Williams and Yeldell's attorney, John A. Shorter Jr., and by the prosecution team of Richard L. Beizer, Schuelke and Lehr.

"A whole trial is a living, breathing thing -- I want them to pick up all the subtleties," said Magarity, who heads the special prosecutions division of the U.S. attorney's office here. "The substance of this, some kind of bribery, well that's old hat . . . .

"But the way the lawyers manipulate the facts, that's important and you can't get that just looking at law books."

"The sex appeal of the case is not why I'm sending them," Magarity added. "I'm sending them to pick up techniques and tactics."

Besides, he said, he wanted to catch some of the action himself: "If you're in the courtroom yourself all the time, you don't get to see others doing it. Trial law is a love of mine, obviously . . . I enjoy watching it."

Cliff Haines, of the district attorney's office, said he wanted the 14 young lawyers who joined his office "to see a master try a case. And I wanted our people to see a well-run, sophisticated trial going on as opposed to the normal run-of-the-mill trial in Philadelphia state courts."

Nicholas J. Nastasi, who unsuccessfully defended Pennsylvania State Sen. Henry Cianfrani in a recent political corruption case, said he found the Antonelli-Yeldell trial "a fascinating case." On Thursday, when "I happened to be down there anyway," he stopped in to see what was going on.

"I really didn't see enough of it," he said. "But I did go up and say hello to Mr. Bailey afterward," apparently referring to Williams.