Unwarping what Napoleon left behind

It sits rather smugly in front of some 18th-century gold-and-white paneling, gleaming like a fat, juicy plum made of wood. It is a chest, but what a chest. The sides are curved, and the front bows out not once, but twice in a serpentine curve. The rounded sides are covered in tiny burnt-edged, 1/16th-inch-thick diamonds of rosewood, in two colors. They look flexible, like fish scales or snakeskin, but they are fixed under a quiet, glossy finish.

The gloss went on by ''French polishing,'' a technique requiring light strokes and many days. Even the insides of the drawers are works of art, curved to fit the fat flanks of the bureau, and lined in herringbone-patterned veneer, just to amuse its owner (thought to be the Duc de Toulouse, a legitimized son of Louis XVI), or, more likely, his servants, as they reached in for the damask napkins to set the table for dinner at the Chateau Rambouillet. The feet, carrying out the fish motif, are gold-plated dolphins plunging, goggle-eyed, through foam. More explosions of golden foam work as drawer pulls. This is not a joke or a dream, it is a bombe commode, made by Gilles Jubert, the king's cabinetmaker, in 1845 in Paris.

But the gleam you see in 1982 here in Boston's Museum of Fine Arts, and its remarkable presence in one piece, are the handiwork of Robert Walker, head of the MFA's restoration and conservation department.

When it first appeared in his workroom - a behind-the-scenes domain full of quaint and/or gorgeous old things that are teetering on loose legs, warped, or covered with dust - it, too, was a mess. The ''carcass,'' or the body of the piece, had shrunk about an inch, and the veneer was in such bad repair that Walker recut almost a whole side's worth of thumbnail-size rosewood scales. ''In its years,'' he said, as he squatted at the side of the chest to show off his scales better, indistinguishible from Jubert's, ''it had lost a lot and they just dropped off through the dryness, and, of course, you know, normal abuse of the base itself, people trying their dab-hand at repairing it. It got to the point where it was just plaster put on.''

Walker speaks with a North of England accent, trilling the ''r's'' a bit, with a gruffness around the consonants the Beatles made familiar.He's animated and bristly. He looks mischievous under a straight fringe of Napoleonic bangs, and anywhere he goes in the museum, especially the back corridors where the staff of picture hangers, electricians, and other technicians cruise on their forklifts or prowl with fistfuls of jangling keys, he is halooed with smart remarks, which he returns just as smartly, or winks at. ''Why do you want to interview himm ?!'' they shout at the reporter, and Walker seems glad to have caused a fuss.

He is proud of himself and his work - his title is director of the restoration and conservation department, but he considers himself a conservator, and he considers conservation an art. He is a fellow of the American Institute for Conservation, and has an artist's temperament. ''Mood is a very important factor'' in his work, he says. ''Rembrandt and people like that were very temperamental. Good conservators are very temperamental people,'' needing to get into the right frame of mind to deal with some of the delicate old finishes and processes that go into their work. They must straighten warps without breaking wood. They must - gently - use chisels to pry off gold plate hammered on at the time of Napoleon. They must not lose a screw, because an 18th-century craftsman made that screw by hand and you can still see his file marks on the threads. They must revitalize wrecks - without taking them apart. They need steady hands, with steady minds behind them. ''If you are frightened of a job, you don't have the right to work on it. You'll make mistakes or destroy it. Patience is the virtue,'' he says sternly.

He gets ruffled by museum hierarchy, and rolls his eyes when he talks about having two bosses, the curators of European and American Decorative Arts. Both departments are buying more aggressively these days, and acquisitions often crowd Robert Walker's workroom, all urgent.

He is earnest about furniture, and his bluster goes away when he talks about the people who made it and their craft. ''When this was built, this was built by a cabinetmaker, elite,'' he says with approval, as he slides one of the clever drawers of the bombe commode shut. ''He knew what he was doing.'' But the chest needed help. ''So, I decided that for one year of my life I would put this back as it should be.''

He took off the old veneer by gluing it to a canvas and peeling it back, to keep all the pieces in order. He cut new scales in the same two types of rosewood and dipped each into sand over a double boiler - ''just for the briefest moment, in and out,'' he says, making a darting motion with his hand - to get just the right burnt edge to give the impression of depth. Every drawer had something wrong with it. One was held together with four big screws. He cleaned the gold froth and fishes in a special solution and then reburnished them by rubbing them with special stones used by the French gilders who made these fancies at the height of the craft. When he was all finished, he and Jonathan Fairbanks, the museum's curator of American Decorative Arts, made a new top of wood to replace the lost marble one. Mr. Fairbanks marbleized it (painted a fantastic fretwork of beige and black grains in a luscious reddish background) and Walker French-polished it. That must be why it looks so smug.

Any piece of furniture that's been looked after by Walker has a gleam that somehow looks more like self-satisfaction than shellac. And most pieces in the MFA have been graced by the Walker touch - here, a new finial, hand-turned and finished to match the old ones exactly; there, a ball for a claw to grip while supporting a chest of drawers. Mahogany eagle wings gleam in their full, earlier glory thanks to Q-tips and water, and platoons of polished brass drawer pulls beam at you like lasers as you stroll through the galleries.

''Anything wood is mine,'' said Walker as we breezed through his audience, the viewers at the museum, who might have been surprised by this small, brisk man in the lab coat making the big claim.

That's a lot of wood, with a lot of different surfaces and grades of shine, coming to him with a lot wrong with it. It takes someone like Robert Walker, with his 14-year apprenticeship to a stern master cabinetmaker in England and his years of experience, to make so bold a claim. Bold? ''One has to be a little insane to undertake such responsibilities,'' he says proudly.

Laying claim to all the furniture, he also feels he is only taking care of it so it can be given over to future generations of fanciers. Everything he does is reversible or redissolvable.That means if anyone wants to undo his year's work on the chest, they can. If they are so inclined, all they have to do is dissolve the shellac, get the scales off, lift the top, and see what's left of the piece as it survived. The hide glue Walker uses - the same stuff they daubed on in the 18th century - is water soluble. The lacquer is made from the droppings of the lac bug in India, which is refined into flakes and then mixed by Walker himself into an amber substance and then licked on with strokes that look as if he's playing a violin concerto instead of holding a ripped-up cotton diaper and shining a chair leg. And all this can be wiped off with alcohol. If a new leg is put on, there's a bit of aluminum foil between it and the old leg that will show up in X-rays.Everything is photographed before, during, and after being worked on, and duplicate records are kept in three locations.

Some curators, Walker says, would, if they had an old table with three legs, display it with a Plexiglas leg, as if to say, ''This is what's left of the original.'' Walker and the curators of European and American decorative arts feel differently. ''We're not here to fool the public. [But] I think people appreciate looking at a piece of furniture as a whole.''

Robert Trent, then an MFA researcher, now exhibitions curator for the Connecticut Historical Society, described Walker's job: ''He has to be able to replicate all the techniques associated with fabrication of the furniture - woodworking, joinery, turning, gluing, finishing, gilding, brasswork, boullework (inlaid decoration), and work with a wide range of materials, any that could conceivably be used.'' This means any that could have been used, in whatever way , in the last, say, five or six hundred years. Besides that, he has to not do quite a lot. ''Conservation is conservative,'' said Mr. Trent. As the conservator gets more experience, ''You don't get less and less scrupulous, you get more and more and more scrupulous, to the point where you're doing very little to the object.''

''Having an aggressive acquisition policy,'' Trent said, ''puts an immense load on Robert. Objects are coming in faster than he can hope to handle them.''

''One has to shift one's thought from one period to another,'' said Walker, who may be working on, at any given moment, ''a high-gloss, spectacular finish, or half-toned,'' or using a dental tool to try to get to the original color of something that has been painted seven or eight times. Once it took him three days to remember a technique he had learned in his apprenticeship to help him come to the aid of a piano whose lid was warped along the spine and whose veneers were rippled. ''You have to know A to Z and you also have to use M, but you might not use it in 20 years.''

Starting at age 14, he worked long days - 8 a.m. to 9:30 p.m., with night classes - under the strict supervision of the master cabinetmaker. Apprentices were only allowed to build new furniture for the first seven years. They couldn't touch an antique until they knew the cabinetmaker's skills. This is how long Walker thinks it should take.

In recent years, conservators have come out of college conservation programs with a lot of scientific knowledge - the field is benefiting from all sorts of new methods of analysis, such as ultraviolet light and X-ray photography. But they haven't got the hands-on experience. Walker, who is proud (to say the least) of his craft, looks down on young technocrats. ''I feel sorry for kids today. They just have the feeling they want to start at the top. They don't want to go through the regular training process.'' Walker came from being foreman for his master cabinetmaker in England to a job making reproduction furniture in Boston, then worked preparing exhibits for the Children's Museum here. In one week, both Harvard's Fogg Museum and the MFA asked him to come work for them. ''One of the great things . . . was that I never applied for a job,'' he says. ''That has a great deal to say for my upbringing in furniture.''

The bombe commode says the rest.