HIS DOG is named Stockman, after the director of the Office of Management and Budget. His magazine is named The Atlantic, after the ocean. His development company is named Boston Properties, after the large eastern city containing one of his town houses, his hotel, his Modigliani, his Chinese cook and his considerable interior space.

He is named Mortimer Zuckerman. He owns other homes, in Georgetown, East Hampton and New York. An observer from outer space would not know what to make of his schedule, since he apparently never sleeps in a city where he has played squash the same day.

He spends hours on the telephone--in airports, in offices full of scale models of industrial parks, in private rooms he owns but rarely uses, dense with leather or designer prints, copies of The Atlantic marshaled like a prospectus on transparent coffee tables--talking with equal intensity about interest rates, the cost of excavation, and Seymour Hersh, the investigative journalist.

"I'm calling from La Guardia," he says, in a precise, boyish voice. "I have 15 minutes before my flight"--to Boston, having played squash at the New York Athletic Club. "The exposure I've gotten in the press hasn't given me much pleasure. I'm reluctant to have any more publicity." He tentatively agrees to an interview, and tells a joke about a woman in the dentist's chair that ends, "We're not going to hurt each other, are we?"

His secretary calls a few days later to cancel the interview. Zuckerman has flown to El Paso to inspect the Mexican border by helicopter with an Atlantic editor, James Fallows, who is writing about illegal immigration, then back to New York for a dinner. Then down to Washington for a board meeting and squash at the University Club, and four hours of radio talk on the Larry King Show, that notable showcase for the publicity-shy, where Zuckerman hard sells his magazine.

We're on a roll at the Atlantic, we've had an extraordinary year--six of 12 issues containing stories making network news--and have really had an impact on the public dialogue. The story of David Stockman was probably the most exciting and most important magazine story to be published in the last 25 years . . .

The success is due in large part to the article by William Greider, then assistant managing editor for national news of The Washington Post, published in December 1981. It was one of the great instances of journalistic inadvertence. In the article, David Stockman opened a subliminal closet, and the skeleton of supply-side skepticism rattled forth. It was the first instance of publicly expressed self-doubt among the Reaganites, and it shook the country.

"It was really accidental in putting The Atlantic on the map," says Greider, now national editor of Rolling Stone, who had written a letter to The Atlantic's editor proposing the piece. "They didn't see it at all in those terms."

Zuckerman's secretary calls back the next day to say her boss has decided he will be interviewed.

Zuckerman calls a few days later to say he won't.

"There's been"--he pronounces it bean--"a kidnaping in Canada involving the Belzbergs," a wealthy family in real estate, friends of the Zuckermans. "It sends tremors through me."

He reinstates the interview, first stipulating that he will not discuss his personal wealth. "Money is tacky. It distorts everybody's perception of my work, and who I may be." He tells another joke. "Did you hear the one about the bull that was given special feed to bring him back to stud? . . . The rancher told his neighbor that it tasted like peppermint!"

To friends he is Mort, at 45 a dauntingly bright businessman who dominates conversations with jokes, but seldom laughs, a generous, driven, uncertain loner who has undergone an extraordinary mid-life correction. In 1982 he was listed in Forbes Magazine as one of the 400 richest people in America, with $150 million, more or less, tied up in real estate. The 1982-83 edition of Who's Who lists him simply as "Publisher."

Between those two antipodes hangs the elusive personality of a man trying to turn bricks and mortar into literature, and tenants into readers, a high-rise Medici--or Back Bay Borgia, depending upon your point of view--who is considering living more or less permanently in the nation's capital.

A friend, asked why Zuckerman likes Washington, says, "Washington's where the president lives, isn't it?"

"Mort would not mind having political influence," says another friend and member of The Atlantic board, Jeffrey Steingarten. "He's quite interested in getting into government."

Zuckerman considers himself a liberal. He is a supporter of Sen. Edward M. Kennedy (D-Mass.), who attended The Atlantic's 125th anniversary party in Boston last year. He says he "likes" Sen. Gary Hart (D-Colo.). Unfortunately, the strict limits on personal contributions in the Campaign Reform Act of 1974 took most of the fun out of campaigns for people in Zuckerman's income bracket, but owning an influential journal of opinion cuts as much political ice as massive contributions used to.

Pressed on the subject of Potomac Fever, Zuckerman says, "I just sort of go with the flow of my life. I'm spending four or five days here a month, soon that will double. I don't want to be separated from my dog, a wonderful dog, the first dog I've ever had in my life--a chocolate Lab. My dog is fabulous!"

Staffers at The Atlantic refer to him, in absentia, as "The Chairman." To his enemies he is a parvenu with an almost demonic grasp for profit. Acrimonious lawsuits involving him and former Atlantic stockholders have polarized scroddy old Boston. "He's a liar and a cheat," says Robert Manning, former editor of The Atlantic who was unceremoniously sacked by Zuckerman, one in a long string of derogations trailing back through the Boston press.

"I'm usually mis-described in the media," says Zuckerman, "except in the National Real Estate Quarterly, which described me as an excellent softball pitcher."

"The softball game's the most important thing in his life," says Joan Bingham, widow of Worth Bingham, heir apparent to the Louisville publishing empire, and a friend of Zuckerman's who lives in Georgetown. "It started when he went out to the Hamptons six years ago, and met those journalists, writers and politicians."

Not just any softball game, but the weekly Sag Harbor softball game. "It's based solely on seniority," says Ken Auletta, a writer for The New Yorker who plays right field. "No businessman had ever been involved. Mort decided he wanted to join, and we all thought, 'Here's a mogul who's just taken over the Atlantic, looking for some new furniture.' But he never talked business, and quietly waited for his seniority to accumulate."

There's a problem, however, with The Chairman's fast ball.

"Some people say he, you know . . . cheats on the mound," says Auletta. "He takes an extra step in front of the rubber."

"People defer to him," complains Judy Klemesrud, a New York Times reporter, and the pitcher for the opposing team. "A lot of the players want to write for The Atlantic, or be editors. We have strict time rules, but if he comes late, he still gets to play. People say, 'We wouldn't have started if we knew you were coming, Mort!' "

He is pouring money into The Atlantic like concrete into new foundations. The magazine has acquired a dozen new staff members, and an entire advertising staff in New York. Zuckerman has hired the advertising agency of John Scanlon, a regular in the Sag Harbor softball game, to flog Atlantic pieces in the media. An Atlantic office is being opened in, of all antithetical terrains, California.

Subscriptions are up to 400,000, Zuckerman says. Advertising revenue increased 40 percent in the last year. He expects The Atlantic to be profitable by the end of next year, 18 months ahead of schedule. That would be remarkable, since The Atlantic lost about $4 million in 1982.

"Have you heard the one about the two missionaries taken prisoner by natives? They're given a choice of chi-chi, or death. The first one chooses chi-chi. They beat him and stick bamboo shoots under his fingernails and boil him in oil, and he dies. The second one says, 'I guess I'll take death.' The head native says, 'A very good choice. But first, chi-chi!' "

Zuckerman gets off the elevator in the District Building in Washington with a retinue of Yankee overcoats. The bureaucrats all stare at him, a waferish version of Woody Allen in hand-tooled banker's stripes, spectacles and loafers with gold stirrups. Zuckerman gazes with mild disbelief at the primitive art lining the corridor--he is an art collector, as well as a developer, with a kind of money nimbus that brokers and political pilot fish cannot miss.

He shakes hands all around. He jocularly grabs the lapel of a mayoral minion, peels it back, reads the label. "I can't believe it!" he says, trying to be one of the boys. "You get a little money, and you start buying Italian suits!"

He stands at a table with Mayor Marion Barry and four other dignitaries, the only white face in a battery of primed political ordnance brought together to bless a piece of real estate, the old Sumner School at 17th and M streets NW, his piece of real estate, being preserved and incorporated into office space.

After the speeches he compliments the assemblage, compliments Washington for allowing such enlightened development to take place, raises a saucer of champagne to his lips but doesn't drink.

Riding back down in the elevator, he jokes with one of the overcoats, a hotshot from Citicorp in Boston, which is putting up some of the $40 million for the project, "That's going to cost you three-quarters of a point. Half a point for the meeting, a quarter-point for the drink."

His grandfather was an orthodox rabbi, "an amazing man," he says, "a wonderful man." Zuckerman's upbringing in Montreal "was perfectly ordinary." His father, a tobacco and candy wholesaler and a partial invalid after a heart attack at age 39, wanted his son "to belong to the community of scholars." Zuckerman awesomely obliged by earning an MBA from the Wharton School, a law degree from McGill University and a master of law from Harvard, all before turning 25.

He also attended the Harvard Business School, a perennial if exceedingly ambitious student. Then, the preeminent real estate firm, Cabot, Cabot & Forbes, made him its chief financial officer. Zuckerman rose quickly, making the company--and himself--many millions of dollars before he went into business on his own.

He also moved from Cambridge digs to a Beacon Hill town house, where he entertained with a certain salon-like intensity. "I suppose he was our Gatsby," says Michael Jane-way, former managing editor of The Atlantic who already lived on Beacon Hill and is now Sunday managing editor at the Boston Globe. "His parties were always good. There were the smart people around Mayor Kevin White, people from The Globe, a certain New York element. He managed to cross the river, which is unusual."

Janeway adds: "You have to remember where Gatsby came from, and where he ended up."

Zuckerman sued his former employer at Cabot, Cabot & Forbes over their shared interest in a building, an early indication of Zuckerman's litigious ways. Even more galling to the real estate establishment was the fact that Zuckerman was chosen by White and the Boston Redevelopment Authority to take on a $225 million project, called Park Plaza, linking Back Bay with downtown. Zuckerman called it "the greatest opportunity in the development business. It's like becoming the editor of The Washington Post."

Zuckermen spent seven years fighting neighborhood organizations and other developers over Park Plaza, during which time the project was reduced to the $150 million range and a pale reflection of Zuckerman's early blueprints. He abandoned them finally, but remained popular at City Hall. His plan for the Long Wharf Marriott Hotel was picked over those of other, higher-ranked competitors, at the expense of the head of the Boston Development Authority who was fired for failing to approve Zuckerman's hotel.

His real estate ganglia reaches as far as California; his interest in Washington is not limited to buildings. Two years ago Zuckerman made a pass at buying The Washington Star; he offered to buy The Washingtonian from its former owner. He is an equal partner with U.S. News & World Report in a $200 million development project in the West End that will include a luxury hotel and new headquarters for the magazine. He owns none of that magazine's editorial product, yet the publishing connection adds resonance to one more real estate deal.

"Washington's a wonderful market," he says, riding west in a taxi through the Pennsylvania Avenue rush hour, looking out at all the construction. "In five years, most of Boston Properties' investment will be in the Washington area. We own Capital Gallery a government office building in Southwest , in the $35 million range. We're going to build Democracy Center"--an office complex on I-270, in Maryland, in the $100 million range--"an industrial park in Springfield, Virginia"--in the $70 million range.

Sometimes, he says, he sits outside his buildings and watches people go in and out.

"To them, they're just buildings. But I've been involved in every stage--I've had to conceptualize the final product and spend money three and four years in advance. Just like with the magazine. You can't just have words, you must have editorial direction, and good art. Just like in a building. A building's not only function, it's also design. In a building you try to create a feeling, a mood. We're trying to do the same thing with the magazine."

Zuckerman is the anthropomorphic link between between big-time development and big-time writing, where literary works are "properties." "For several years I had been thinking of a new career," he says, of his decision to buy The Atlantic in 1980.

"My God," says Garth Hite, the former publisher. "when he wants something, is he persistent!" Zuckerman made a dozen offers, according to Hite, the final one for $3.6 million. "He told me, 'Garth, all I'm trying to do is save culture in Boston.' "

Some thought culture already secure there, among them a syndicate including members of the Winthrop family that offered $3.9 million. But the syndicate was unwilling to commit itself to new operational funds for the magazine, should the sale go through. So, says Hite, "We were dumb enough to sell it to Mort."

Zuckerman had discussed the future of the magazine at length with Manning, the editor since 1964 and a distinguished journalist picked from the groves of Time-Life. Yet Manning did not suspect that entrepreneurial hardball would be played within The Atlantic's auspicious brownstone. "For all his experience," says one of Manning's collegues, "Bob is one of the most honest and innocent people I've ever known."

Manning championed Zuckerman, the potential buyer, to a Brahmin cattle-breeder named Marion Campbell, who owned the magazine. Then the new owner fired him. "Manning had lost his editorial fast ball," Zuckerman says. To illustrate his own adeptness in the firing, Zuckerman told associates the joke about the accomplished Chinese executioner. ". . . The victim looks up after the sword has fallen, and says, 'I'm still alive.' And the executioner says, 'Move your head.' "

Then, chi-chi! He refused to make subsequent payments to Atlantic stockholders, arguing that the financial prospects of The Atlantic had been misrepresented to him by the sellers. "So much of the way I work is emotional," says Zuckerman. "I was misled and mistreated, and I couldn't let it go by."

Hite and the other stockholders say Zuckerman got a good deal, with 20 years of certified audits to prove it, and was simply offended by criticism of the Manning affair. They filed suit for the money; Zuckerman countersued. The matter is still before the courts.

Zuckerman has sold the building housing The Atlantic to himself, as a tax shelter. Should he lose the suit, or should he choose to give up the magazine if it does not pan out as an investment, he will still own the only tangible piece of property associated with The Atlantic, in a prime Boston location.

A Boston businessman who is a member of Zuckerman's Atlantic board says, "Dealing with Harvard law school graduates, lawyers and accountants, you soon learn that a bill is just the beginning of negotiations. Mort's got staying power. He can drag this thing out for years, and have use of the money all that time."

"The tone of the criticism here," says an Atlantic editor, "was that Mort was this new rich person who bought the magazine so he would be invited to dinner at the Kissingers. He's already been to dinner at the Kissingers."

But flying around in a chopper over the Rio Grande in the company of a writer is more fun than eating fruit compote in the aeries above Park Avenue. It is even more fun, believe it or not, than the Sag Harbor softball game. And owning The Atlantic gives Zuckerman more luster than merely owning $150 million worth of buildings, some of them hung with American abstract expressionists.

"I ran into Abe Rosenthal executive editor of The New York Times ," he recalls, of a gathering in New York. "I told him about a marvelous article in The Atlantic about Auschwitz. Abe said, with characteristic modesty, 'I wrote the best article that's ever been written about Auschwitz.' He read the article anyway, and I got a letter which he dictated to his secretary from a phone booth in O'Hare Airport, saying how marvelous the article was."

The headhunt for the new editor took Zuckerman to Europe via Concorde to speak with the likes of Harry Evans, then editor of the Observer in London. He also considered Greider, Janeway, William Broyles, now editor of Newsweek, Michael Kinsley, who later became editor of Harper's, and about three dozen others before finally settling on William Whitworth, then an editor at The New Yorker.

Zuckerman courted the impersonal Arkansan who wears Brooks Brothers crepe soles and fills the margins of manuscripts with incisive, spidery scrawls. "We spent a lot of time together in New York," Zuckerman says. "We had dinner, we had breakfast. We talked about everything. We got to know each other on many different levels . . . We have a fabulous working relationship. He's brilliant, a wonderful, wonderful human being. There's something so simple and elegant about his clarity--a complete man."

"How many times in life does someone offer you a magazine and give you the means to run it?" asks Whitworth, sitting on a hard chair with his new view of the Boston Public Gardens. "I had heard stories about how tough Mort was, how he moved fast and had power and influence, that no matter how good his intentions were, constitutionally he wouldn't be able to keep his hands off. Well, he's kept his promises, and he's been a cheerleader."

The offer included a car and a reputed annual salary of $100,000. "Mort's clearly infatuated with Bill," says a friend of both men. "Some of us wonder what would happen if that infatuation were to end."

"Bill says that our readers should feel like they're sitting in someone's living room," says Zuckerman, with undiminished enthusiasm, "listening to a very intelligent, lucid person discussing the issues."

Just like reading The New Yorker! Formerly an impoverished journal of great diversity, Zuckerman's magazine came to resemble The New Yorker Book Digest, even The New Yorker Book Digest Devoted to the Works of Robert A. Caro, whose biography, "The Years of Lyndon Johnson," was excerpted in five issues of The Atlantic. (Caro's previous book, the Robert Moses biography, "The Power Broker," was excerpted in The New Yorker.) Whitworth told associates shortly after he took over the editorship that The Chairman wanted a fast, impressive fix and finished manuscripts by established authors--the opera dei of the confabulatory marketplace--were the safest bets.

Book excerpts remain the backbone of the new Atlantic, what a competitor calls "a beautiful vessel into which beautiful words are poured." Those beautiful words cost: $75,000 for the Caro material, $75,000 for two excerpts of "The Price of Power: Kissinger in the Nixon White House," by Seymour Hersh. The book excerpting has made Zuckerman inordinately popular among New York publishers. "They're thrilled and amazed at what he's done," says a literary agent. "He can't be ignored."

Zuckerman leaps out of the taxi and disappears into his town house, a block off Wisconsin Avenue. He emerges carrying a Head bag containing his squash racquet, followed by an Oriental maid in crisp white polyester.

"When you watch the furniture?" she screams.

Zuckerman just waves at her from the back window. "She wants me to look at some furniture I ordered. The house is in the process of being organized--I've only had one meal there, last night was the first time I've slept there. I'm not trying to force it. It'll happen if it happens. Moving is not something I decide."

He always thought he'd be married "and have six kids and a humdrum professional life. It hasn't worked out that way. There's not enough time . . . It will happen in its own time. I would like to have a family and a marriage and children and a dog and a picket fence. I've always loved kids. I get along fabulously well with them, I really talk their language, and they mine. Which reminds me of that story of the 80-year-old man who goes to the doctor, and tells him . . ."

"Mort has dated every woman on the East Coast under the age of 45," says one of them, a New Yorker. "He's great for one day," says another, a Washingtonian. "He concentrates on you, and makes you feel terrific. But on the second day it's the old tycoon cliche' again--always on the phone."

Lesley Stahl, the CBS White House correspondent, met Zuckerman 10 years ago in Boston where she was a reporter for Channel 5 and Zuckerman was the developing wunderkind who had just left Cabot & Forbes. Her recollection of those years is foggy: "We went to a concert together. I remember driving down a big highway in a sports car." It was Stahl who exposed the issue of The Atlantic containing the Stockman piece to the White House kliegs, causing Zuckerman to call the next day, and say, "You just increased our subscriptions by 200,000."

The cab has arrived in the environs of the Sumner School, just down M Street from the Jefferson Hotel. "Here we had to deal with different facades of different sorts of buildings," says Zuckerman, "and introduce modern office space. It's an opportunity to do something imaginative, just like writing different kinds of intriguing stories. As the French say, Tant mieux!"

The cab turns into the University Club. "No, no, I'm playing at the Capitol Hill Squash Club!"

"Man," says the driver, "where are we goin'?"

"I've always had this notion of building blocks," says Zuckerman, as the cab plows back out into 16th Street. "You know, until something's really solid I'm a little reluctant to commit myself. The Atlantic is really going well enough. We're opening an advertising office in California, hiring ad people in New York. We have our television roll-out, a huge mailing. If it all goes well . . ."

"I don't think Mort cares about getting his money back," says Bruce Gray, the first publisher Zuckerman hired, and then fired.

Certainly, Zuckerman has a bleak view of the economic future upon which his magazine is dependent. "I have no reason to expect our economy to turn around. The conventional wisdom says that we're in control, but in fact we aren't in control. I see no reason to think we'll pull out. I think I've told you my favorite story about the guy in bed with the woman, and her husband walks in. He asks her, 'Where's your back door?' She says, 'We don't have one.' He says, 'Where would you like one?' "

He climbs out of the cab, and goes to the locker room, where he strips and puts on a red headband and a brace for his tennis elbow. He grips his racket and looks around for an opponent, looking like a principal in an E.F. Hutton commercial.

"This administration reminds me of the two guys manacled to the wall of a dungeon. They're hanging a foot above the floor, both have long beards and rags for clothes. One turns to the other, and says, 'I have a plan' . . . If things go on like this, all a Democrat will need to win is the nomination."

And all Zuckerman will need, if he gets a call from the new president, is his Head bag.

"It's fascinating, in a sense, to see all this happening, and to wonder whether or not your perceptions of reality are accurate. I've cut back tremendously. We have an over-hang in terms of our total square footage of less than 3 percent. If you have that low a rate of vacancy, you can ride through anything. And we've financed everything we needed to finance ourselves, we have a great deal of liquidity."

Whatever happens, The Chairman's covered.