"Pretty nutty, isn't it?" said Mark Ferguson, a local painter, staring at artist Damien Hirst's enormous shark suspended in a case of greenish formaldehyde at the Brooklyn Museum of Art.

"Oh, that's cool," said psychotherapist Adam Melaney, eyeing Marc Quinn's bust formed from nine pints of his own frozen blood. "Using your own organic matter to create a self-portrait."

In an alcove around the corner, crowds stood quietly before "The Holy Virgin Mary," denounced by New York Mayor Rudolph W. Giuliani (R) as a religious insult because artist Chris Ofili had placed a decorated clump of elephant dung on the Madonna's chest like a jeweled broach and surrounded her with magazine cutouts of buttocks. Many declared the collage beautiful. Graphic designer Martin Ponce wasn't sure. "Hmmm, interesting," he said. "Definitely interesting. I'm not sure what to think about it."

After a furious week that brought dueling lawsuits, a steady cadence of invective from the mayor (who opined that "this should happen in a psychiatric hospital, not in a museum funded and supported by the city"), and a countering flurry of demonstrations and statements by artists and free-speech advocates, the museum's exhibit of hackle-raising contemporary British art opened today to a public eager to see what all the fuss was about.

Faced with long lines of visitors, museum officials opened the show, "Sensation: Young British Artists from the Saatchi Collection," six hours earlier than planned. Metal detectors had been installed at the entrance, and Ofili's Madonna stood sheltered behind a sheet of Plexiglas, flanked by two guards.

Outside, bus loads of Roman Catholic protesters prayed and sang in the fall sunshine; a small group of animal rights demonstrators and a few free-lance critics waved placards; and one protester was arrested after police asked him to move and he refused.

But despite the city's decision to cut off the museum's funds and attempts to evict it from its city-owned building, the show went on. "We're very much hoping that, as is characteristic of New Yorkers, people will decide they wish to make up their own minds," said museum director Arnold Lehman. "And the way to do that is to come and see the exhibit."

An early ripple of public-opinion polling indicates that the mayor's attacks, which his opponents suspect have much to do with his expected senatorial campaign, may not be playing well in Brooklyn--or in Peoria. First, a Daily News phone poll of 508 New Yorkers, published Friday, found that 60 percent agreed with the museum's position that the withdrawal of city funds violated its First Amendment rights. Only 30 percent, including a minority of his fellow Catholics, sided with Giuliani. Nationally, the University of Connecticut's Center for Survey Research and Analysis conducted a phone survey of 500 adults and found that 57 percent agreed that the museum had the right to show the artworks.

Nevertheless, the city's attempts to force the cancellation of "Sensation" markedly intensified over the past week. At first, Giuliani described the exhibit, which he repeatedly branded "sick" and "disgusting," as an affront to religion that should not receive taxpayer funding. The museum responded with a federal lawsuit charging that his attempt to withhold $7.2 million, nearly a third of its annual budget, was unconstitutional.

Then city officials claimed that the museum was in violation of its 1893 lease--which calls for public access--because it requires children to be accompanied by adults and because it is charging a $9.75 admission fee for the "Sensation" show. Both policies, selling tickets to special exhibits and barring unaccompanied young children, have been in place for years. But the museum scrambled to admit youngsters to deprive the city of legal ammunition.

Expanding its arguments, the Giuliani administration added another alleged offense to its list: that by showing works owned by a single collector, British ad magnate Charles Saatchi, the museum is improperly enriching a private individual and Christie's, the auction house co-sponsoring the exhibit. A deputy mayor denounced the exhibit as "hucksterism" and "a scam."

In general, an artwork's market value tends to rise after being displayed in a major museum, particularly amid a vortex of international publicity. But Christie's, which helps underwrite several museum exhibitions each year, said it is "bewildered by these accusations" and that the 90 works in the exhibit--already seen in London and Berlin and bound next for Australia--are not for sale.

The city filed its own lawsuit in state court on Thursday, seeking the museum's eviction and damages. The museum, adding several counts to its complaint on Friday, is now seeking punitive damages from the mayor. Arguments for a federal injunction are scheduled to be heard Friday, but the legal wrangling may continue longer than "Sensation," slated to run until Jan. 9.

After days of uncomfortable silence, the city's usually vociferous creative community mounted a counteroffensive. Some art world veterans muttered that the powerful Saatchi, with the mayor's assistance, had neatly manipulated the media to draw attention to his holdings, but a number found the prospect of Giuliani serving as "arts czar," as one dealer put it, even more distasteful. "People have gotten over their shock and disbelief and are in outrage mode," said Joan Bertin of the National Coalition Against Censorship.

The Cultural Institutions Group, 33 city-funded organizations from the Bronx Zoo to the New York City Ballet, issued a public statement expressing concern, though it required five tortuous days. The PEN America Center took a full-page ad in the New York Times, signed by more than 100 prominent playwrights, artists, writers, choreographers and actors, condemning the mayor's actions. Free-speech advocates staged a rally outside the museum Friday and held a candlelight vigil tonight.

No one really expects the mayor, whom the New York Civil Liberties Union has sued nearly 20 times during his six years in office, to reconsider his stance. "Once he stakes out a position like this, he will never back down until he loses in court," said Bertin. "And when he loses, he criticizes the judges."

But a number of today's visitors credited Giuliani with drawing their attention to an art world event they might otherwise have ignored. It attracted 7,000 people, believed to be a museum record, in its first seven hours. "I'm going to come back next week," declared Christine Feldman, who was only temporarily discouraged by the opening-day throngs. "I've got to see this exhibit."