FOR Americans, it was buried treasure, until the National Gallery mined and mounted the sumptuous new show ``The Treasure Houses of Britain.'' From the castles, palaces, and so-called ``country houses'' of Great Britain's nobility has come a deluge of beauty: 800 treasures ranging from priceless paintings by Rembrandt, Gainsborough, Rubens, Sargent, El Greco, and Constable among dozens of others, to sterling silver furniture, a Faberg'e Easter-egg necklace, Queen Victoria's antler settee, the Praxiteles 4th-century BC ``Aphrodite,'' and Thomas Chippendale's ultimate dollhouse.
Patrons for the show are the Prince and Princess of Wales, whose arrival Nov. 10 to view it has generated a king's ransom in publicity.
Sumptuous is the word for this show, which is subtitled ``Five Hundred Years of Private Patronage and Art Collecting.'' It draws from the works of art collected between the 15th and 20th centuries in over 200 houses in England, Ireland, Scotland, and Wales; houses whose collections rival those of major museums. Among the great houses included are Castle Howard, the setting for the ``Brideshead Revisited'' series on TV's ``Masterpiece Theatre,'' Blenheim Castle, Woburn Abbey, and Warwick Castle.
Paradoxically, the gilded Treasure House show has been housed in I. M. Pei's ultramodern East Wing of the National Gallery. There the huge red and black metal petals of an Alexander Calder mobile sway over collections begun in 1485 with the Tudors. But the National Gallery design and installation staff have transformed the wing into a historic showcase, a time warp of the arts.
This is such a vast, rich exhibit that each viewer can choose his own focus. But be sure to allow between two and three hours, and wear hiking shoes, because it encompasses 35,000 square feet, all of it dazzling. A taped audio guide provides an incisive and witty comment for the exhibit by J. Carter Brown, director of the National Gallery. He proposed to the British Arts Council in 1979 that his museum mount a show on the British country house as ``a vessel of civilization'' for the past 500 years.
The exhibit begins with the Tudor Renaissance Gallery, filled with art from the late 15th and early 16th centuries, when the country house and its collections began. It contains the magnificent life-size Lumley Horseman (originally from Lumley Castle), an equestrian statue of King Edward III carved in 1580 from oak-stained mahogany, scarred and pitted with age. On a facing wall hangs the fascinating ``Rainbow Portrait'' of Queen Elizabeth I holding a rainbow in her right hand. She wears a silk clo ak that matches her red-gold curls, a cloak printed with eyes and ears as a symbol of her network of informants.
Next is a Jacobean Long Gallery, one of the most stunning rooms in the show, modeled after a 16th-century portrait gallery shown in the painting of the Countess of Arundel by Daniel Mytens which hangs here. The National Gallery's chief of design and installation, Gaillard F. Ravenel, his deputy chief Mark Leithauser, and the exhibit's curator Gervase Jackson-Stops re-created the Jacobean gallery by duplicating samples of the pale green glass windows from Hardwick Hall for the leaded diamond-shaped panes , and reproducing the look of aged tan sandstone by using layers of quartz crystals suspended in an epoxy resin. Gil Ravenel, who spent 31/2 years on the project, says that their objective in each room was ``to create settings in which everything fits.''
In the art of the Scottish Highlands room, for instance, the walls are covered in a navy-and-green Black Watch plaid; ``that [plaid] was not done as a caprice,'' he points out, but in the tradition of many Scottish treasure houses. In this room sits Queen Victoria's bizarre antler settee cushioned in moss-green worsted; overhead hangs Sir Edwin Landseer's masterpiece of a stag facing his rival across a loch. Across the hall lies Winterhalter's dramatic 1849 portrait of the Duchess of Sutherland, holding
pink roses, from Dubrobin Castle.
As you move through the rooms, the portraits dominate. In the ``Dutch Cabinet'' room it is Rembrandt's luminous painting of ``Old Woman Reading,'' in which light from the book, possibly the Bible, illuminates an eternal face. Van Dyck's powerful 1629 painting of ``The Betrayal of Christ'' rivets the attention in the Augustan Room: A wall-sized oil of Jesus holding a symbolic blood-red robe and compassionately gazing at Judas who holds his hand as the soldiers close in.
In the Waterloo Gallery, there is an embarrassment of riches: a 1606 Rubens portrait of the Marchesa Grimaldi, resplendent in a silver-white gown; Titian's 1540s portrait of Marquess Savorgnon in black velvet and ermine, and Vel'azquez's 1636 painting of a young Spanish prince in black, nonchalantly riding a rearing black pony. Perhaps the most symbolic painting for this exhibit is John Singer Sargent's magnificent 1905 group portrait of ``The Marlborough Family,'' with the black-caped Duke, his A merican wife (Consuelo Vanderbilt), and their children staring down bigger than life from the country house known as Blenheim Palace.
``Treasure Houses'' is also rife with gorgeous furniture, porcelain, jewels, tapestries, and sculpture. But a few objects are sure to be special attractions: among them, in the Chinoiserie room, a great state bed, early 18th century, from Calke Abbey. Its blue Chinese silk hangings wound with dragons, flowers, and pagodas hadn't been unpacked until this show, so its colors are fresh and bright; if you look closely, you'll see the peacock feathers woven into the fabric.
In the ``Triumph of the Baroque'' room gleams the most baroque of all objects, embossed silver furniture: table, looking glass and stands, dating from 1676-81, from the King's Room at Knole.
There are whole rooms devoted to subjects like the Palladian Revolution, Souvenirs of Italy, the Country House Library, Edwardian Elegance and the Sporting Life (a wonderful collection of George Stubbs portraits of horses).
Apart from the very great art, one item is sure to be one of the most talked-about hits of the show: the final entry, a 1735 wall-sized dream of a dollhouse attributed to the legendary furniture designer Thomas Chippendale.
``Treasure Houses,'' organized in collaboration with the British Council, the National Trust, and the Historic Houses Association, and sponsored by the Ford Motor Company, runs through March 16, 1986.