SOUTHAMPTON, England -- The Ashmolean Museum in Oxford is generally acknowledged to be the world's first modern museum worthy of the title. Unlike its predecessors, it was not just a cabinet of curiosities -- archaeological relics and anthropological wonders amassed by some explorer and shown in his own home. Nor was it a rich man's art collection that stayed firmly attached to his walls but still called itself a picture gallery. The Ashmolean was specifically designed for the public display of its collection -- and therein lies the difference.

Since Oxford's museum opened its doors in 1683, thousands of museums and art galleries have been built all over the world. As the years pass, all of them, whatever their vintage, type or geographic location, come to share a common headache. Permanent collections, like little Topsy, just grow and grow, but museum buildings do not. Nowhere is this chronic lack of space more acute than in Britain's museums, where inheritance and tax laws have long encouraged the bequest of works of art or artifacts to public collections. Indeed, many were founded on the basis of the generosity of a single individual and then added to over the years by the museum's own acquisitions.

Besides the storage problem, administrators must consider the issue of conservation, which is particularly thorny in the case of paintings. The sad fact is that, no matter how inspirational and otherworldly a painting may be, it is first and foremost a physical object, containing organic matter that is vulnerable to decay. When the work in question is one of the jewels in the crown of a museum's collection, it is likely to be on permanent public display in a climate-controlled gallery, where its condition can be monitored daily. But works like this are always in the minority. Down in the basement of any museum, one finds the rump of its collection -- works that have been acquired over the years through bequest or curatorial choice and yet have subsequently been judged to be of inferior artistic quality. The museum may hesitate to display them publicly, but the obligation remains to preserve these works in optimum condition for posterity. Languishing in the storeroom, however, they deteriorate physically, chemically and organically, and the museum may lack the resources to conserve them in prime exhibition condition.