The lean, distinguished man was recognized in National Airport as he waited for the plane that would take him home to Boston. Passengers came up to him and said that they had relatives in Nahant or Milton or that they had seen him in Boston or somewhere. He turned to a companion and said this was commonplace stuff. "You see, all you have to do to meet the world is walk with me . . . "

Henry Cabot Lodge, Jr., world traveler and politician and diplomat, at 78, is yet another faithful war horse, like Averell Harriman, who had come to the Hill to extol the virtues of the SALT II treaty.

They were both world travelers in a time that now belongs to history -- Harriman knew Stalin and Churchill well. Lodge knew de Gaulle and Churchill and Kruschchev. And they are not unalike -- vestiges of a time when the well-born felt it their duty, as well as a distinct pleasure, to play statesman.

They came from the right families and the right clubs and the right schools and wore the right ties and married the right women and lived in the right houses and possessed the right (old) money. And yet they mingled with the masses -- Harriman dealing with the Democratic ward heelers; Lodge defeating that legendary master politician Gov. James Curley eons ago (1936) to become the senator from Massachusetts.

The political road carried Lodge far from the Senate; Eisenhower's ambassador to the United Nations, Nixon's vice-presidential running mate, Kennedy's and Johnson's ambassador to Vietnam and Nixon's ambassador to the Vatican.

Now, at 78, Lodge is still the sartorially correct aristocrat; the impeccable lightweight tan suit and thin-striped blue-and-white shirt with the simplest of small initials H.C.L. embroidered on one side above the trim waistline. His personality has its paradoxes. There is effortless charm in his easy politician's handshake, his affable twinkle that makes you think that in a burst of intimacy he will tell all.

But his mingling with the masses goes just so far. He has outlived most of those famous men with whom he shared history -- but breeding and diplomacy triumph over longevity. The little intimacies, the playful or biting reminiscences are not dropped.

Legend has it that one reporter, in his cups once crossed the outer limits of Lodge's bonhomie. Lodge had imbibed a bit, too, and the interviewee and interviewer were having a grand old time until the reporter draped his arm around Lodge's shoulder. In an instant, the back went ramrod, jostling the arm loose. Enough was quite enough.

Not that Lodge is stuffy, mind you, even though he is a Cabot and a Mayflower descendant and despite that 1910 Holy Cross Alumni Dinner toast by one John Collins Bossidy. "And this is good old Boston/The home of the beam and the cod/Where the Lowells talk to the Cabots/And the Cabots talk only to God."

Lodge is told that journals of the past described him as "lady-killer of the first water." The blue eyes sparkle. "D'you suppose I had any fun?" Then, as if musing to himself, "as the French say, 'It is not excluded. Ce n'est pas exclus.'"

It was the morning after Labor Day, and the roomful of reporters were sluggishly shaking the somnolence of vacations. Americans For SALT, a nationwide citizen campaign pushing ratification of the treaty, brought forth its co-chair, Lodge, plus Leon Lynch, a vice-president of the United Steelworkers Union, and David Cohen, president of Common Cause.

Lodge's face in repose is heavy-lidded, but animation takes years away. His voice is raspy. "The specter of a nuclear war is a distinct dread in the minds of the American people." SALT II would slow down a "dangerous and wasteful race in nuclear weapons." Lodge stresses that this agreement "in no way relies on trust or good faith." Eight years in the U.N. taught Lodge that relying on faith was "not worth much." The strategic arms limitation treaty talks flow "directly from the American and Russian recognition that there must not be a nuclear war. Let us continue the course we are on. It is a good beginning."

He pulls a diplomatic Lodge-dodge when reporters try to corner him on Carter: "Well I thought President Carter handled the Panama Canal Treaty very ably." And he seemed genuinely bemused when asked whether the disclosure of Soviet buildup of combat troops in Cuba could endanger the SALT negotiations. "I don't think it has a direct bearing on SALT II. All we have to do is look at the alternative of no SALT II. That's a convincing enough argument."

Lodge is in good form as he relaxes after the conference. He recalls the spring of 1960, when Nixon picked him for a running mate. Lodge had a political score to settle with Jack Kennedy, who beat him for the Senate in 1952, although he said at the time, "If I hadn't lost to Jack I never would have had eight years at the U.N., and I might not be running for vice president." They also were personally good friends. "He lived near us in Georgetown and we had him over quite often."

"I told Nixon, 'well, Dick, I've been in this work all my life, and I don't have to worry about money. If people like me are not going to aspire to these offices, who is going to do it? But you'll have to draft me. It's too late to go out and run for it. Give work to all your henchmen and I'll be nominated." He laughs as he recalls the phone call a few months later in July, leaping up to mimic the quaint phrase of an old southern Senate colleague. "There I was -- sleeping in the only place where a man of honor should lie -- next to the wife of my bosom. And it's 4 a.m. and Nixon called and said he had gathered 80 of the leading Republicans of the country and all agreed I should be nominated for vice president. I said, 'I accept and I will do my damnedest.' And we did, but it wasn't enough."

He knows the question is coming: his honest thoughts on Nixon. Lodge sighs. "Is there any way I can put a set of words together that won't get me into a great deal of trouble? Which doesn't interest you," he adds with a smile, "but interests me to some extent."

It is time for the reporter to sigh -- Lodge has found the words. "I know him well. A man of great energy and physical strength and drive. I think I'd better stop there." Watergate was a "total" surprise. "He had his faults -- but going for the dough! That wasn't in his character at all. Not only did I know him. I knew his mother quite well. She was a splendid person." Nixon and Lodge have not talked for some time. "I sent him a Christmas card."

In 1964 Lodge quit as U.S. Ambassador to Vietnam to mastermind the unsuccessful "stop Goldwater" attempt, and Lodge won the New Hampshire primary on a write-in. He still clings to the moderate Republican faction in increasingly conservative times. "I'm for (George) Bush. I think he is a decent, generous, open-minded guy. I don't know what his 'ism' is -- although I think we all have to have an 'ism.'" Lodge utters a sentence that sounds like some offbeat slogan: "Bush would please a lot of people in the future -- who don't even know him today."

Senator Edward M. Kennedy gets muted praise. "He's a grower. He's done some growing -- and he's going to do more." Lodge will not wager on the outcome of 1980 or Kennedy's chances, turning the question onto himself. "I'm not running this year." Wide grin. "I think '84 is my year."

Lodge turns suddenly forthright on former U.N. Ambassador Andy Young. "His behavior is exactly consistent with what he thought and felt and he wasn't making any pretense. When a man of his distinction and stature is acting in an absolutely sincere way that is not the time for everybody to be shocked. I should imagine that was one of the reasons the president selected him.He does a lot of talking and you have to do a lot of talking when you're in that job. Young was potentially a great asset."

The theory that Young was a fall guy and was not alone in talking to the P.L.O. is ventured. Lodge's eyes widen and there is slight disgust. "Well, of course . . . If you had the relationship that I had with Eisenhower, you'd never be in trouble. While not the most brilliant man we ever had, you have to give him credit for thinking of ways of doing things without hurting a lot of feelings. He was a smooth operator."

In his day, Lodge talked tough with the Russians, often bluntly, and earned the respect of Khrushchev for it.

He approves of Carter's firing of cabinet members. "I don't know enough about the individuals involved, but I feel that after one year, the president ought to fire a few people -- even if they are excellent." He pauses and says, "this interview, if it's ever published, will make me sound like an absolute idiot."

In all his years of politics, he disliked running for office, a fact well hidden to the reporters who covered his tireless campaigns. "Managing someone else's campaigns. That is fun. I managed Eisenhower's. But yourself! Having to get up every morning and tell everyone what a great guy you are. That creates nausea, but you have to do it.

Lodge's grandfather and namesake, Henry Cabot Lodge -- who first served in the Senate in 1893, and was a confidant of Theodore Roosevelt -- advised Lodge to go into journalism and "avoid the awful nuisance of politics." Through the years, biographies add that his grandfather also said "besides, it's the best training for politics."

That, says Lodge, is "journalistic mythology. Where would the press be without cliches?"

After he worked on the old Boston Evening Transcript and the New York Herald Tribune, the pull of politics was too much. After all, six of his forebears had preceded him to the Senate, and his family produced a Secretary of State, Secretary of the Navy and a Governor of Massachusetts.

At 78, Lodge, a shade under 6'3", still has the bearing of a former athlete. A superb horseman and sailor in his youth, he also captained a Harvard crew. Lodge became the first senator to resign to serve in a war, and came out of World War II with six battle stars, a Bronze Star for Valor and two French decorations -- the Legion d'Honneur and the Croix de Guerre.

He says little about his own role in Vietnam and prefers to talk of peace. "I am a trustee of the General Marshall Foundation. I think he (George C. Marshall) was the greatest man we had in the 20th century." And he also seems sanguine as hell about being "older than Methuselah."

"The Marshall foundation interests me, and then I'm in a lot of local things in Massachusetts, and I spoke out for the Panama Canal Treaty and now this SALT II thing and my book ("As It Was") for some inexplicable reason is doing well."

The final twinkle is there as he heads for the plane. "I say 'inexplicable' -- because there is not a dirty word in it!"