Artist William Adair is looking for his goatfish. So are the police.

You'd know it if you saw it. It has a scaly, fishy tail growing from its head. Its yellowed, foot-long teeth are tipped with Russian gold. Its hoofs are gold-leafed, too. The pupil of its eye is gleaming silver-gilt. William Adair's goatfish is pot-bellied, peculiar. It is also eight feet tall.

For 13 months the goatfish had been staring at pedestrians from its second-story niche on the facade of the LeDroit Building at 8th and F Streets NW. On Saturday a goatfish thief -- who had brought along a ladder, metal-cutting tools and a large brown van -- climbed up to its perch 15 feet above the street, snipped its steel leash, and carried it away.

"He had to hustle," says Adair. "At first I was flattered the thief wanted it so badly. I'm not flattered anymore. It would have been nicer if he'd bought it."

The goatfish was on sale for $5,000.

A small grant from the city government helped pay for its materials. It was made last summber -- of gessoed, gilded styofoam -- for an invitational Studio Gallery show called "Maquettes for Monuments." Adair still has his little stoneware maquette, but his monument is gone.

James Taylor saw it go. Taylor is a street vendor who sells necklaces and earrings below the pedimented portico of the National Portrait Gallery on the F Street mall.

"I looked up and saw this guy putting up his ladder," said Taylor. "He was thirtyish and blond and bigger than Mr. Adair. I said, 'Hey. You're not the artist.' He said he had permission from the owner of the building, and from the sculptor, too, and that both of them had told him to take the piece away. It wasn't easy work. He had lots of trouble with the steel cable."

"Good," said Adair.

"I liked that animal a lot," said Taylor. "Everybody like it. It was a real tourist attraction. People came and took pictures of it all day long. The guy said he was going to put it in a sculpture garden. Hell, if I had known they were giving it away, I'd have taken it myself."

Adair, 31, is the National Portrait Gallery's conservator of Frames. Another of his sculptures, this one of an eagle, is in the permanent collection of the National Museum of American Art. Adair's Gold Leaf Conservation Studios Inc., across the street from that museum, restores gilded furniture for the Corcoran, the Freer, the White House, and the State Department's reception rooms. White House curator Clement E. Conger calls Adair "a master gilder."

He was working for Conger, applying gold leaf to an 1815 table made by Charles-Honore Lannuier, when he first conceived the goatfish, which he has titled "Homage to Lannuler."

Adair, whose studio is at 715 G St. NW, is one of many sculptors who, in recent years, have been adding works of art to the streetscape of downtown, a neighborhood, of late, that has been much improved by the public-spirited artists who exhibit or reside there. Thirteen of them, in recent works of art in store fronts and in parking lots only a few blocks from the LeDroit Building where the goatfish used to perch. "Luminous Art for the Urban Landscape," their scattered exhibition, is a $40,000 project of the WPA. Theft of public sculpture there had not been a problem -- until the goatfish disappeared.

"I've had a terrible week since it was stolen," said William Adair. "Maybe it will bring bad luck to the thief." Photographic Medley

The open exhibitions regularly organized by Gallerie Triangle, 1206 Carrollburg Pl. SW, give artists from such places as Waukesha and Cherry Hill what may be their only chance to exhibit in the capital. The photography show on view there now, because it mixes local art with art from far away, is a useful little survey. It is not a daring show. The pretty, if conservative, pictures remind us of the images -- of mountain lakes or bowls of fruit, of breaking waves, trees, and white New England churches -- that non-avant-garde Americans have been hanging on their walls for the past 100 years. Bernard Rupp of Waukesha, Wis., is represented by a geometric study of telephone booths and bricks and black slanting shadows. Also impressive are the misty landscapes of Washington's Carole Clem and the pale still lifes -- a white tablecloth, a white claw-footed bathrub seen against white tiles -- by Carol Samour. The show runs through the month.

Capital Images

Most of the city views -- of Logan Circle, Dupont Circle, the Washington Monument, the World Trade Center and the National Gallery of Art included in "A Positive View of Urban Life," in the fourth floor offices of the U.S. Conference of Mayors, 1620 I St. NW, are more interesting than postcards, but not much. Most of these pictures are as stale in style as they are in subject, though Carol Jeffers' picture of the National Gallery's pyramidal skylights brings unexpected freshness to a landmark that has been photographed to death. Al the photographers participating are members of the Washington Women's Art Center. Their show runs through the month.