When The Renwick sent out announcements

that its 10th birthday was coming up, artists sent in fanciful proposals for birthday cakes. The gallery accepted 14 based on how the artist used the media, whether part of the building was incorporated in the design and how close the proposal came to the Platonic ideal of cakeness. At the Renwick's birthday party this Sunday from noon to 5, guests can see the special cakes in the Grand Salon. You won't have to bring a present to get a balloon and see the juggler, magician and tapdancers, or listen to the mandolin-players and Gilbert- and-Sullivan song-singers. The cakes will be there through April 25, during which time some are not likely to go stale -- one made from neon, another crocheted. We were able to sample the birthday cakes in advance, most of which were too pretty to eat. The Renwick building housed the city's first art museum, which opened in 1874, but from 1899 on it was used by the U.S. Court of Claims. Then, 10 years ago, the building was once again "Dedicated to Art," as is inscribed on the facade, when it became the Smithsonian's museum for American craft and design. The French Second Empire-style building has been distorted in a whimsical way in a birthday cake by local artist Eve Watts. She rounded off its corners, fashioning from white earthenware a delicious-looking Renwick with a mocha glaze. It sports pigeons in its crevices and lovebirds on its cornices. A couple of gallery-hopping birds are leaving; the male of the species is donning his coat. Even the candleholders perched on the rooftop are birds. Niches in the wall hold statues; true enough, there are two such statues on the real Renwick. But Rubens and Murillo did not have bills! As his birthday gesture, another Washingtonian, Tim Evans, focused on the statues, which he copied in unbleached muslin. Sturdy pieces of fluff and nonsense, each two-foot-tall doll carries a cake with a single candle. With capes trimmed in lace doilies and pearl buttons, and long curly hair made from yarn, Rubens has green sequin eyes and Murillo blue. Then you spot THE CAKE. Tiers fill your eyes. How can clay be froth? "A real tour de force in the use of porcelain," is the way Bill Wilhelmi's cake was described by Raylene Decatur, who helped organize the show. Ringing the bottom layer are animal heads: Minks? Something reptilian? Pig mice? They're snouted critters, coiffed in '40s hairstyle or wearing a pastel flowered bonnet, having tete-a-tetes in Garfinckel's Tea Room fashion: "Madge, where did you get that hat?" they all seem to be saying. "They are nothing discernible," said Decatur. "There's no animal like that. We should probably be glad." Another cake would be appetizing only to the metal-toothed goon nicknamed Jaws in Ian Fleming's "The Spy Who Loved Me." It is the coldest cake in the show -- a cake of steel, by Jan Brooks Loyd. Its starkness is mitigated by the homey "Happy Birthday" scrawled on top. It looks rather like a bowling trophy. Birthdays are full of surprises: inside a pale blue satin travel case one finds a soft mocha cream cake. A slice of it shows off its fine texture: brocade. There is also a home- baked marble cake, swirled in blue, garnished with home-baked marbles. Small slices of cake with candles already on them will be on sale in the museum shop; flavors range from chocolate chip mint to chocolate with red icing to devil's food with white icing. They are entirely inedible, being made of silk, with stickpins on the back for fastening on one's lapel. Decatur summed up the show of birthday cakes. "The thing I like is the mix," she said. THE INEDIBLE RENWICK BIRTHDAY CAKES -- through April 25.