FIVE CENTURIES OF MASTERPIECES -- At the Corcoran Gallery of Art through November 30.

Armand Hammer has done it again. Last year, the wealthy industrialist and art collector pledged more than $1 million to the Corcoran Gallery to eliminate admission fees and to help with renovation of the building. Now he has outdone himself with "The Armand Hammer Collection," a traveling exhibit on view through November in the Corcoran's atrium galleries.

"My satisfaction in assembling this collection is complete only when I can bring it to others," writes Hammer in the handsome catalogue to this lush and lavish showing of masterworks from five centuries.

For its part, the Corcoran has responded with a fine installation in its skylit upper atrium: Soft, natural light cascades down cream-colored, uncrowded walls as the chronologically ordered display carries the viewer from room to room. (One gallery, artifically lit and carefully darkened, is reserved for some of the subtler drawings that don't hold up in the natural light.)

Of the hundred-odd works on display, most have not been seen before in Washington. Among the newcomers are two important paintings by Rembrandt van Rijn: "Juno," an oil-on-canvas portrait of the mythoogical queen of the gods, is considered by some to be the crown of the collection; and "Portrait of a Man Holding a Black Hat," a realistic oil on a wooden panel, probably depicts one of the artist's well-to-do patrons.

One of the show's earliest pieces is an elegant gouache on vellum done by Albrect Durer in 1526 as part of a colorful series of botanical studies; with masterful attention to detail, Durer created a "Tuft of Cowslips" that shimmers with delicate hues of green and yellow. Other early items on view include a page of studies drawn by Leonardo da Vinci (circa 1560) and a study for a fresco by Raphael (circa 1500).

Paintings from the 17th century include three oils by Peter Paul Reubens, "The Israelites Gathering Manna in the Desert" among them. From the 18th century, there are works by Fragonard and Goya.

Among the best works from the 19th century are John Singer Sargent's "Dr. Pozzi at Home," Gilbert Stuart's 1822 "Portrait of George Washington" and Mary Cassatt's delightful "Summertime," to note just a few. Andrew Wyeth's lovely watercolor impressions of "Brandywine Valley," Modigliani's "Woman of the People" and a pair of drawings by Picasso are among the 20th century's representatives.

Other artists represented in this important collection include Bonnard, Chagall, Corot, Cezanne, Degas, Eakins, Gauguin, Monet, Remington, Renoir, Seurat and Van Gogh.