"Inscape," an oddly-shaped hollow steel sculpture by Ed McGowin, used to glow with an elegant, eerie inner light. Today it stands like a moody dead weight in the foreground plaza of an office building at 1220 19th St. NW, where it was installed with fanfare and high hopes a decade ago.

Funded in part by the National Endowment for the Arts in collaboration with a local museum and a private developer, the piece was a real treat -- a provocative, witty, engaging work of public art. Passersby, looking inside through four small windows cut into the corners, could behold a strange, neon-lit tableau of artifacts placed there by the artist to indicate its edgy inhabitation by an imaginary soul.

But "Inscape" has been in its present spiritless condition for more than two years, ever since a thief, operating in the dark with a tool capable of loosening so-called "tamper-proof" screws, broke into the sculpture and took away, among other things, a pair of bronzed shoes; a bronzed hat, wallet and fountain pen; a stool; and several lengths of steel cable -- all parts of the interesting, ambiguous story McGowin was trying to tell. The thief also broke two neon signs, the source of that strange inner glow. Ironically, each read, "Do Not Touch."

McGowin, a New York resident who was one of Washington's pre-eminent artists when "Inscape" was commissioned, visited the site yesterday on his way to install an exhibition of his recent works at the Osuna Gallery downtown. "My feelings are pretty predictable," he said. "I'm sort of devastated that the piece was vandalized and that the responsibility of restoring it, if it ever is to be restored, is all mine. I would do almost anything to put the piece in first-rate condition at little or no profit, but I can't do anything without the permission and support of the people that own it."

McGowin said he twice offered to donate his time to fix the piece, but was rebuffed. One proposal, in which the cost of materials was estimated at about $2,500, was simply to restore "Inscape" to its original condition. Another, at an estimated cost of $4,700, was to improve the work by enlarging the windows and applying cast-metal exterior borders with relief images relating to the narrative tableau inside.

"Inscape," which originally cost $16,000, half provided by the arts endowment and half by the developer, now exists in a sort of physical and moral limbo. No one seems quite sure what to do with it.

Edward McCullin, an official of Louis Dreyfus Property Co., a major partner in 1220 19th Street Holdings, owner of the building in front of which the sculpture stands, said, "We would like to find a good permanent home for the sculpture, where it would not be abused and vandalized. We'd be perfectly willing to donate it."

Laughlin Phillips, director of the Phillips Collection, the museum that served as official sponsor of the sculpture in the application for the matching grant from the arts endowment, said, "If there is an application to the endowment or to anyone else to fix it, we would be delighted to join in."

Renato Danese, the former arts endowment official who oversaw the grant application 10 years ago (he is now director of the Pace Gallery in New York), said, "There is an implicit understanding when such grants are made that the grantee will maintain the art work." Micheal Faubion of the endowment's visual arts program confirmed that "though our guidelines suggest ways to go about fund-raising, maintenance and so on, this is not a legal contract. Once the grant period is over, our legal involvement ceases."

The curious tale of "Inscape" raises two important questions that are of increasing interest to artists and arts officials nationwide. The first concerns often nebulous or nonexistent provisions for maintaining public works of art. The second concerns the relative rights of artists and owners to control an artwork, once it has been sold. The idea of placing contemporary artworks in the public domain, after being dormant for nearly three decades, was rekindled by various federal and local governments and by private corporations during the late 1960s and early 1970s. "Back then people just thought about getting the work out there," commented Jenny Dixon, executive director of the Public Art Fund, the agency that supervises compliance with New York City's one-percent-for-art legislation (whereby 1 percent of construction costs are spent on art). "But we've realized that you have to deal with the maintenance issue up front. You have to deal with it in a contract at the beginning."

Clearly no such conditions applied when "Inscape" was commissioned, and the situation is further complicated by the fact that, even though obviously placed in a way that makes it a "public" artwork, the piece is privately owned.

In 1983 the New York state legislature adopted the Artists' Authorship Rights Act, which states that "the physical state of a work of fine art is of enduring and crucial importance to the artist and the artist's reputation." The law permits artists during their lifetimes to sue for damages or to halt objectionable alterations to their works by private owners. Ironically, the first legal battle under terms of the new law was enjoined by Robert Newmann, another former Washington artist, who filed suit to prevent a private developer from altering or defacing a partially finished mural on a building wall in Manhattan.

But "Inscape" is protected by no such law. "Maybe the owner can be coaxed or shamed into doing something," commented Donald Thalacker, director of the art-in-architecture program of the General Services Administration, which recently won a Presidential Award for Design Excellence. "It is a terribly important piece, one of the first contemporary works to grace the cityscape here, and it reflects the artist's subsequent development."

The GSA commissioned a $50,000 McGowin "inscape" for Jackson, Miss., in 1979, and the artist currently is working on a $30,000 "inscape" commission at a Veterans Administration Hospital in Indianapolis. "This one on 19th Street was a key piece, all right," McGowin said. "I've spent the last 10 years developing the idea."

Laughlin Phillips deserves the last word. "I walked by there the other day," he said, "and I'm very distressed. It is one of the few interesting examples of street sculpture in the city."