On Tuesday, the name of American oil tycoon Armand Hammer appeared on the outside wall of the little-known Museum Jacquemart-Andre, housed in an exquisite turn-of-the-century mansion on Boulevard Haussmann.

"It's only right that your name should be next to the founders of this museum," said Rene Huyghe, director of the museum, as he unveiled the plaque saying that the Jacquemart-Andre is now an Armand Hammer Foundation beneficiary.

Hammer has already given close to $1 million and promised $500,000 more for the 10 years to come. At a dinner the night before, he started announcing he would give $250,000 for the next five years, and then, probably caught by the French ambiance, changed his mind (or looked as if he did) and announced that he was doubling that figure. Applause.

The dinner, hosted by the Huyghes at the museum, was a clever blend of high society, friends of the arts, academicians and Nobel Prize winners. The official accolade was personified by Mrs. Raymond Barre, wife of the French premier.

Hammer apparently saw the museum four years ago when he tried to have his collection displayed at the Louvre. The Louvre was booked solid for a year ahead. He was sent to Huyghe, a distinguished art historian who belongs both to the Academie Francaise and the Institute. The latter owns Jacquemart-Andre.

The museum was originally owned by Edouard Andre, who had it built in 1875 to house his collections. He later met and married Neli Jacquemart, a painter who had come to do his protrait. Hence the name, Jacquemart-Andre. The two of them accumulated an eclectric assortment that ranges from the Italian Renaissance to the 18th century, including Rembrandts, Fragonards, Guardis and four Chardins, which Hammer said, are "the best in the world." With its period furniture, Sayounneries rugs, Aubusson tapestries and flowers in Chantilly and Sevres vases, the house also has a rare lived-in feeling.

But it was in a sad state when Hammer first saw it. An air-blowing furnace was ruining the expensive marquetry, the gilt around the walls and ceilings had gone to seed and the paintings (with a large collection of portraits, the owner's favorite) were in need of cleaning and restoring.

"They needed me," Hammer said. "I fell in love with the museum. It was love at first sight. I was also moved by the desperate state it was in -- floor leaking, ruined furniture and paintings being damaged."

Hammer, who developed a fast and strong friendship with the Huyghes, had his collection displayed at Jacquemart-Andre in 1977, and it attracted 100,000 visitors. The money he has given has made conspicuous changes already. The entrance hall and the main salon have been restored to their original gilt-and-cream splendor, as have the painted ceilings. The furniture is slowly being put in shape, and the music room has been lined with pale suede and hung with the Italian Renaisance paintings, including works by Carpaccelo, Ucello and Mantegna.

"Fiive years from now, you won't know this place," Hammer said. "I hope I live to see it."

Hammer looks like he will more than make it.

At 82, small and sprightly, he still keeps a pace that would kill a man half his age. Paris was just a stop in between Vienna ("where I looked at 41 Durer originals, but I want you to know, mine are better") and Rome, where he will be received by the pope. Recently he started a new collection of Daumiers. No modern art, though. Not interested.

"Maybe I'm old-fashioned," he said.