ART EXHIBIT. The estate house as art -- `Treasure House' show goes to America

When the last great door of the last stately home has closed to the public at the end of the open season, more than 200 of home owners will pack up some of their greatest treasures and send them to the National Gallery of Art in Washington, D.C. This isn't a mass sale of Britain's heritage. It's ``The Treasure Houses of Britain,'' the biggest exhibition of art from British houses ever to leave the country.

Over 700 items have been selected to travel to the United States. The items span the half-millenium in which the British aristocracy has been creating country houses and stocking them with the finest works that could be bought or commissioned. Together, the items will bring to the National Gallery the distilled essence of the British country house phenomenon.

The formidable task of choosing from among the contents of more than 700 estate houses has fallen upon Gervase Jackson-Stops, and no one is better qualified to do the job.

Seconded from The National Trust, where he is architectural adviser, he is intimately acquainted with almost every country house worthy of the title, and has written profiles of them for the magazine Country Life. Working in close conjunction with the director of the National Gallery of Art, Mr. J. Carter Brown, he aims to present the country house, not just as a great repository of international works of art and a must for tourists, but as a work of art in its own right. How the houses came to be

Mr. Jackson-Stops explains how the British country house became what it is. While Italian nobles built their pallazzi in cities, and the French centered their lives on the court at Versailles, the British shunned the formality of court life and spent as much time on their country estates as possible, returning to their London town houses only for ``the season.'' Houses great and not so great were set in the peaceful countryside, the landscape itself conforming to the fashion of the day -- from the geome tric plan of the Renaissance garden to the ``natural'' landscapes designed by Capability Brown, which were inspired by the idealized visions of Claude and Poussin.

The exhibition will highlight the range of interests that were indulged in settings as near to perfection as art and ingenuity could contrive: the sport and the animals that were central to country life; the romanticism seen in the recurring waves of nostalgia; the broad intellectual and scientific works from the great libraries. The Renaissance ideal is clearly visible in the diversity of the objects and the human scale. It was mostly a secular world, as can be judged from the many portraits and landsc apes and the paucity of devotional objects.

Contributing to the uniqueness of the British country house is the simple fact that so many have survived. While wars and revolutions decimated the European nobility and their collections, Britain -- except during the 17th century -- remained undisturbed by destructive conflict. By far the greatest damage to this collective heritage has come through social and economic changes during the last 50 years.

The country estate was an autonomous entity with extensive agricultural lands that supported not only the ``big house,'' as estate houses are still called today, but all who lived and worked on the property. The depletion of the land holdings through death duties and the rising costs of maintaining half an acre of lead-lined roof have led many owners to retreat to the nether regions of their ancestral piles and turn the state rooms and parks into organized businesses. Most owners prefer this sacrifice t o the soft option of selling their increasingly valuable works of art for a short-term gain.

Political objections to the possession of so much potential wealth in a few hands become less relevant in view of the great burdens such responsibilities now incur. This has long been recognized in the exemption from estate duties of works of art of national or historic importance, provided the works remain accessible to the public. But many feel that the burden of maintaining such houses is becoming so heavy that without more government assistance in tax concessions further depletions of the heritage w ill be inevitable. Fine art's answer to orchestrated music

The piecemeal disposal of the contents of a houses erodes the rich effect of the whole. A great collection in the setting for which it was created is fine art's answer to music: It can move us with complex responses to the orchestration of landscape, architecture, painting, sculpture, and decorations. The sale of the Harewood desk -- designed and made by Thomas Chippendale for the builder of Harewood House in Yorkshire -- seemed at the time like selling the opening bars of Beethoven's Fifth Symphony. Th e totality of the country house experience is also enhanced when the house is still occupied as a home, for homes they are and not museums. The state takes on the temples of taste

There is a long tradition of opening the great houses to the public. Some have always been open ``upon application to the housekeeper.'' Very few today are not receiving some form of support from public funds, which binds them to open their doors to the public. As the state takes on more of the responsibility for these temples of taste, it is necessary that we fully appreciate what they mean to us.

This is what ``The Treasure Houses of Britain'' exhibition aims to do.

While it is splendid that the importance of our peculiar heritage is to be brought so vividly to the notice of a wider public, there appear to be no plans to show the exhibition in Britain. As this is where the responsibility for the future of this glorious past ultimately resides, it is perhaps at least as important for the British public to be exposed to the vision of the organizers and sponsors of this exhibition.

The exhibition runs Nov. 3- March 16.