A new classic in the annals of melodramatic political rhetoric, Lt. Col. Oliver North's appearance before the Iran-contra committees yesterday ranks right up there with Richard Nixon's "Checkers" speech and Franklin Delano Roosevelt's complaint that the Republicans had stooped to attacking even "my little dog, Fala."

North stopped short only of taking out family photos of his wife and kiddies or getting down on one knee for a chorus of "Swanee." It was bravura, it was electric, it was vaguely deplorable but it was fascinating to behold. It will be studied for years in universities, political forums and, perhaps, medical laboratories.

Viewers may have feared the tension and electricity might fade on this, the second day of North's boffo stint on Capitol Hill before the House and Senate select committees investigating the circuitous logistics of the arms scandal. But, at least during the morning session, North was raring to go, and went.

Once, after some procedural wrangling between his lawyer and the committee counsel had ended, North looked up eagerly and said, "Whose turn?" It was a Rambotic gesture, like a hero in a war movie standing up with guns akimbo, looking the onrushing enemy squarely in the kisser and shouting, "Come on, come on, let's see what you've got!"

The emotional high point, and quite a sustained one, came when House counsel John W. Nields Jr. made the tactical error of asking North about that $16,000 security fence that went up around his house and was paid for by one of the contragate conspirators.

"If you'll indulge me, I'll give you another of my very straightforward, but lengthy answers," North said. He wasn't kidding. At least not about lengthy. North then launched into a rambling but compelling narrative about how bloodthirsty terrorist Abu Nidal, "the world's foremost assassin" and a "brutal murderer," put North's name on a hit list and made him fear for the welfare of his family.

"I'll be glad to meet Abu Nidal on equal terms anywhere in the world," North said with a swagger (and this guy can swagger sitting down), but when anybody starts messing with his wife and daughters, then look out, they're in deep mud. Denied protection by the U.S. government, North said, and unable to get a security company to make a prompt estimate and begin construction (any homeowner would believe that), he reluctantly accepted what he thought was an $8,000 system that later turned out to cost more.

And, gosh, like a darned old silly, he rigged up two "phony documents," later, to make it look like he'd paid for the security system himself. The way he explained it, it was the kind of thing that Ozzie Nelson, Chester A. Riley or even Cliff Huxtable might just as easily have done.

North was prompted, he said, by accounts of the Vienna airport massacre, during which an 11-year-old girl named Natasha Simpson was viciously murdered. "Gentlemen," North said, with an audible lump in his throat, "I have an 11-year-old daughter not perhaps a whole lot different than Natasha Simpson." Point made, and then some.

In the course of the security saga, North said that he "made an effort" to have a news story about the terrorist threat on his life "killed," but complained, "CBS chose to run the film anyway." CBS News officials, who said they were initially confused by the reference, yesterday traced it to an April 29, 1986, report on "The CBS Evening News with Dan Rather" by correspondent Doug Tunnell.

Tunnell reported that, in reprisal for the U.S. bombing of Libya, Abu Nidal's group had targeted for attack not only North and Maj. Gen. John Singlaub, who previously testified to the committees, but also the Heritage Foundation, the right-wing think tank. CBS spokesmen said other networks reported this story, too, and they didn't know why North singled out CBS in his testimony.

North also spoke of the late CIA director William Casey's advice to him that "I should be prepared to take my own life" if things got particularly nasty as a result of the arms deal. As grim as the testimony got, it had a tendency to give way at unexpected moments to exotic absurdity, as when, just after mentioning suicide plans again later, North proudly declared, "I never, ever, heard about bellybuttons until these hearings began."

"Bellybutton" was one of the code names for North that cropped up in documents obtained by the committees. "Joshua" was the code name for President Reagan. The proceedings included quotations from memoranda that would probably be deemed too hokey should they be included in a James Bond script: "If these calculations are acceptable to the banana, then oranges are ready to proceed."

"Banana," North explained, was Israel, and "oranges" the United States. Among its many other satisfactions, the North appearance before the committees has some of the mordant intrigue of a John le Carre' thriller.

Then, suddenly, it's "Get Smart." North was asked about checks made out to the Parklane Hosiery store, allegedly out of collected contra funds, ostensibly to buy panty hose for North's knockout secretary Fawn Hall, who had previously testified.

See here, that visit to the Parklane Hosiery shop had nothing to do with Fawn Hall's panty hose, said North, setting the record straight on this world-shaker. For one thing, "Ollie North has been loyal to his wife since the day he married her," quoth Ollie North. And the payment to Parklane was for leotards for his little girls. North said his wife had reminded him of this, referring to him as "you old buffoon" when she refreshed his often-parched memory.

Much to the disappointment of some detail-minded viewers, the committees never did get around to the matter of North's supposedly ill-gotten snow tires. Maybe today.

On the stand, North continued to stretch more emotive and rhetorical muscles than all the Barrymores put together. Now contrite, now accusative, now coy, now disingenuous, now proud, now sheepish, now feisty, now weary, he was a whole season of Broadway theater rolled into one roller-coaster morning.

But one of the most stunning moments of television during the morning had North briefly off camera. While he continued his testimony, CBS and NBC, and later ABC, cut to live shots of Ronald Reagan leaving the White House to board a helicopter for a trip to Connecticut, where he was to make another speech on his economic dream plans.

The juxtaposition was eerie and incriminating; the little guy, the lieutenant colonel, was sweating it out on the hot seat, practically a sacrificial functionary, while the top man in the chain of command could be seen waving and smiling and larking about, looking coldly and unfeelingly oblivious to North's plight. It was one of the ugliest images of Ronald Reagan's presidential career.

It couldn't have helped Reagan, or hurt North, that the afternoon session began with a close-up of the many medals on North's chest. The camera then zoomed out to take in the rest of the Senate caucus room. Ollie, Ollie, Ollie. Is it actually possible you will ever be prosecuted for your errors and sent off to prison? Would the American people stand for it after watching this Herculean performance on television?

Perhaps for the first time since the hearings began, one felt a jolt that indicated a pivotal historical moment had occurred -- Reagan looking suddenly Nixonian as he clambered onto the chopper, North looking seduced and abandoned as he sat there misty-eyed in front of his amassed accusers.

North seemed to be heading a place in mythical history somewhere between Billy Jack and Billy Budd.

The morning was divided chiefly between North's plaintive monologue about death threats and suicide plans and his lawyer Brendan Sullivan's muttered instructions and advice into his ear. It was "Cries and Whispers." Sometimes the lawyer did the crying, as when he carried on to diminishing effect about how the committee counsel was clearly stalling and conspiring to keep North around into next week.

"Let the record show that it took 4 1/2 minutes to explain the 'stall,' " barked Sen. Daniel Inouye (D-Hawaii), Senate committee chairman. Even North later asked his lawyer to cool it, placing a paternal hand on his shoulder and saying, "Please counsel," to forestall an objection. As usual, Inouye would brook no nonsense. If only he had been nominated to the Supreme Court. He knows how to handle lawyers.

For the networks, covering the North appearance has been mainly a matter of turning on the pool cameras and sitting back. Dan Rather of CBS and Peter Jennings of ABC have been especially helpful in filling in background on figures referred to in testimony and in delineating chronologies (Jennings more helpful than Rather, actually). Tom Brokaw of NBC shows his usual incisive intelligence, but he doesn't seem to appreciate the passion and drama of the event. Or of any event.

As soon as testimony ends, the networks tend to skedaddle, pausing briefly to trot out their own correspondents. They have to relinquish the space to their affiliates, who are anxious to parade their local news shows and commercials. In Washington, surprisingly, NBC-owned WRC-TV cut away from Brokaw's summation on the network so that it could start its own shabby, tacky news program at 5 p.m. Lead story: Ollie North, of course.

The Baltimore CBS affiliate, WBAL-TV, dropped Rather's coverage at noon for its own quaint, provincial news show, but the Baltimore ABC affiliate stayed with the network feed, as did the NBC affiliate.

CBS seemed sluggish at times, straying too long with its yackety correspondents and missing some of the action, if incidental action, on the floor. Then, after the hearings, while North strolled out to a waiting microphone to make a statement, CBS clung to Rather and colleagues. All North did was to "thank the tens of thousands of American people who have communicated their support," but it was worth reporting.

PBS doesn't have to vamoose so quickly, so Judy Woodruff is able to buttonhole committee members after the session and get their reactions on the air. Inouye praised North to Woodruff yesterday as "a superb witness" who is "very articulate," but he stopped short of saying he found him credible.

Viewers apparently do. According to an ABC News poll reported by Jennings, 58 percent of those watching say they find North believable, and 70 percent say they think he is "performing well." Performing well? That is an understatement. If the Emmy were a medal, and there were any more room on Ollie North's chest, he would be a shoo-in.

Rather opined that North is "probably the most powerful lieutenant colonel in the history of the United States." He has materialized at these hearings like some ghost from the past, a straight-arrow, duty-honor-country, loyal-to-his-wife type who one might have thought now only existed in movies. He is John Wayne in "They Were Expendable." He is John Garfield in "They Made Me a Criminal."

He is Errol Flynn in "The Charge of the Light Brigade."