In 1939 Washington had precisely one gallery, besides the Corcoran and the Phillips, where you could look at modern art. It was the Whyte bookshop and gallery at 17th and H Streets, and the man you saw there was Franz Bader, a refugee from Vienna who had been hired for $25 a week.

Today there are upward of 135 galleries in greater Washington, and Franz Bader is still here, and then some. He has his own gallery, of course. He has shown us the work of whole generations of American artists, from Gene Davis to Grandma Moses, has gently introduced us to Eskimo art--as early as 1946--and Haitian art and African bark painting, not to mention so many local painters, sculptors and printmakers that they are now actually an official category: the Washington artist.

He is also about to turn 80, and tonight his gallery will be packed to the rafters with the artists he has exhibited and encouraged, some of them coming from as far away as California, along with collectors, art groupies and friends.

For Franz Bader, "friends" has a special meaning. "When we came to Washington, there was not much art," he calmly understates, "but there was enormous friendship offered us. Friendship was everything I really wanted to have. It was always the most important thing."

So 5,000 people have been invited tonight, and at least 1,000 will probably show up. And more throngs will pour into the Art Barn's cake-and-champagne party Sunday, the day before his actual birthday.

The actual birthday, Sept. 19, has been declared Franz Bader Day in the District. And after that, on the 22nd, the Austrian Embassy will have a party to show photographs that he has taken on his travels around the world. And all over town, the art establishment people were polishing up testimonials . . .

His father sold flour wholesale, and his mother was an amateur painter. But he wasn't interested in flour. He got a job with Vienna's oldest bookstore, Wallishauser, and by 1937 had risen to partner. Then the Nazis came, and like other Jews Bader was forced to a radical decision.

"It was not a hard decision to make. As a Jew in Vienna I can't sit on a park bench. I can't go in a restaurant or coffee shop or a movie. I was detained once for several hours. I was a witness to Kristallnacht when Nazi vandals smashed the shop windows of thousands of Jews in Vienna and other cities . After that it was only a question of where can you go."

He tried to get visas for himself and his wife Antonia to England and Australia but was refused. At the American Embassy, he got hold of some telephone books and wrote to every name that sounded like Bader, seeking someone to sponsor the two of them. A Philadelphia school teacher, Mary Baylson, responded, providing the necessary affidavit. But then her letter was lost or stolen in the bureaucratic confusion, along with the Baders' vital quota number.

"The Quakers helped us to get the quota number back," he says.

(The American Friends Service Committee of the Quakers will benefit from Bader's show opening tonight, a retrospective of paintings by artists he has represented through the years. "I am not a religious Jew," Bader says, "but refugees are refugees and people who are persecuted are people persecuted. This international organization helps on a human-to-human basis.")

Next, Bader's passport was questioned, but a sympathetic clerk fixed that up by simply tearing out a sheet that was supposed to have been removed anyway. (For anyone acquainted with central European bureaucracy, such initiative was almost a miracle.) Then, the visa. They still had no visa. It was the end of the day. They were exhausted from their efforts.

"Look, the American consulate is just around the corner," said Antonia, "let's just try it on our way home."

The Americans had two visas left.

The Baders arrived in America with $12 and a derby hat. ("All I knew about America was from reading Jack London, Upton Sinclair and Sinclair Lewis. I thought I needed a derby hat.") They brought with them their culture and their fear. They came to a country where not only did people have meat to eat, they actually cut away parts and ate only the choice bits. And bread: they threw bread away, actually threw it away if it wasn't fresh.

"I carry German books in my store," Bader says. "It's not because I love them. I lost my father in Auschwitz. But if you know one another, then you respect one another and the hatred can't be as bad. People compliment me on this attitude and say how wonderful, but it is not wonderful. It is natural. It is only sad that not more people do it."

James Whyte ran the bookstore; his brother Donald had an art gallery on the second floor. It was a time when "modern art" was to laugh at in Washington. Bader sold two Raoul Dufys for $250 each, a fair-sized Cezanne oil for $12,000.

In 1952 Bader opened his own place at 17th and G, soon afterward moving to 2124 Pennsylvania Ave., and in 1979 to 2001 I St. He still sells art books along with paintings and prints. (Sabina Yanul, who runs the book operation, has been with him for 17 years. "I'm part of the inventory," she says with a laugh.)

No one is quite sure when the first Washington artist came to be represented by Bader. They were always there, his friends--"I never had a written contract with an artist"--whose work he liked.

There was the day Lee Weiss brought in some watercolors, and Bader, busy, said to just leave them and he'd get back to her. Ten minutes later he looked at them. And jumped for the phone.

Peter Milton was getting $75 for his large, eerily dreamlike etchings when he first showed at Bader's. Now they go for $3,500. At the time of Bader's 70th birthday the artist said, "Franz was my first gallery, and now, 10 years and 20 galleries later, he's a dear friend and still the most important gallery to me."

The Art Barn show of prints selected by Bader includes 32 artists, all of them "his." He mutters that he missed the Washington color school, which is to say he didn't ride its popularity to fame and fortune. Too much publicity, he says. He scorns bandwagons. "I have the right to be wrong, too."

He is not, some critics have said, a scholar or a prophet. Still, he showed Gene Davis in 1956, just three years after the color-stripe movement started. He showed Kenneth Noland "when he was still painting like Klee." He was on the jury that awarded the late Howard Mehring a scholarship at Catholic University, where he was to meet Noland and be influenced by him.

To Bert Schmutzhart, a sculptor who teaches at the Corcoran and has always shown his work at Bader's, the man is like a father.

"He never takes just a casual interest in people; he has an incredibly good sense of good art. He was born with it. And a business sense: He might say, 'Well, Bert, I've seen that somewhere before, but let's try it anyway,' or he might say, 'I think you could go a higher price on this one,' or else he'll surprise you and call and say, 'I hope you'll forgive me, but I sold your sculpture for $200 more than you said.' "

There have been more artists than Bader can remember. There was Alma Thomas, another of his discoveries here, and Anne Truitt and Mitchell Jamieson. There were the Eskimo primitives ("the last great folk art; their life is changing so, with TV and all"), the Ethiopian artifacts, the harsh etchings of Gunter Grass, paintings by Mrs. Dean Acheson . . .

"I get excited, enthusiastic," he says. "I need enthusiasm to live, like a fish needs water."

The house, near Foxhall Road, is full of books, Bader's early love. Many are signed with messages to him, as are some of the artworks that cover the walls ("You were the first--Peter Milton"). Many of the authors were given autograph parties when they came to town: Rachel Carson, Dame Edith Sitwell, Dylan Thomas, Aldous Huxley, St. John Perse, Robert Graves, Stephen Spender and so on. Memorabilia, the infallible sign of a walking Washington institution, are everywhere: a funny sculpture of Bader with beard and camera; a serious portrait bust; a photo of Harry Truman, who used to drop into the shop; gold medals; a painting by Bader's wife Virginia, who brought her work in one day for him to show and whom he married a few years after Antonia died of cancer in the early '60s.

They have become travelers, taking off at least once a year, often by camper, for Africa, Central Asia, Samarkand, Siberia, a three-month trip up the Amazon, any place that has art and maybe a ruin or two. Bader takes color pictures along the way, sometimes what he calls tourist photos, sometimes interesting details--an elephant's footprint, a ripple of water, a shadow--things that most people don't see, things that make the planet a beautiful place for him. They may not be Stieglitzes, but they are not trying to be.

Bader, who used to work a nine-hour day six days a week with no lunch, plans to cut back to three days a week after his birthday. He is interested in Pieter Brueghel, the elder, the 16th-century Flemish painter whose work contains, Bader has discovered, coded references to the Spanish occupation of Holland. The subject fascinates him.

"You see this allegory of the Slaughter of the Innocents, the soldiers in the background are Spanish. And the last picture, the gallows and magpie: That was a message to his wife not to talk about all this. And the famous picture of Icarus falling: Icarus is just a detail; the picture mostly shows a peasant at work. This came after a visit to the great Renaissance centers of Europe. All that uproar while those others peacefully toil the earth . . . "

He doesn't want to write about it, just to study, to read, to learn.

After the monthly openings at the gallery, the Baders customarily give a party at home for the artist. "Everyone's on a high at an opening; the artist is excited and all," remarks Virginia Bader. "It seemed a shame just to end it at the gallery."

The result is that the Baders are famous for having one of Washington's most charming and relaxed salons. They are getting a little tired of it, they admit.

One suspects they will not let the custom become a compulsion. Franz Bader takes things as they come.

"I could have sold cars," he says. "Or flour. I could have been rich, so I would have enough money to buy some of the stuff I had in my own gallery. But I wanted to work in beauty. That was more important than the money."