Museums in the nation's capital such as the National Gallery of Art and the Smithsonian Institution's American Art Museum and National Portrait Gallery are closed indefinitely. Also closed are federally run museums such as the Smithsonian Institution's National Museum of the American Indian, in New York.

Wednesday marks day two of the partial shutdown of the U.S. federal government, due to an extremist faction of Republicans in the House of Representatives. The legislators are refusing to pass any measure to fund government operations that does not defund the Affordable Care Act, or Obamacare, as the program is often referred to. Approximately 800,000 federal workers are currently furloughed without pay.

House Republicans have submitted bills to keep popular institutions such as the Veterans Administration, the national parks, and the Smithsonian open during the shutdown. Democrats have dismissed this move as a publicity ploy.

"We have 6,400 employees," said Linda St. Thomas, spokesperson for the Smithsonian Institution, reached by phone on Tuesday. "About 680 of them are working, most of them security guards. The rest are furloughed without pay." She pointed out that after the last government shutdown, in 1995, Congress voted to pay government staffers retroactively.

The smaller staff at the National Gallery of Art is nearly 100 percent furloughed, said museum spokesperson Deborah Ziska. The museum has 807 full-time federal workers, as well as part-time employees and others, for a total of just over 1,000, she said. Those who are furloughed are locked out not only from their offices, but also from e-mail and voicemail.

The furlough is not affecting all museum staffs equally.

"What's different for the Smithsonian Institution," St. Thomas added, "is that of our 6,400 employees, only about 4,200 are federal. The Smithsonian, while it's a federal museum, is not a government agency, so we have an endowment and various other private sources of funding. We are the only institution of that sort."

While national museums charge no admission, the shutdown does impact their income due to loss of revenue from cafés and retail operations. "Last week we had 400,000 visitors at the zoo and all the museums," St. Thomas said, and added, "And that's the off-season."

Some popular exhibitions are already being impacted.

When the shutdown occurred, the National Gallery was in previews for the exhibition "Heaven and Earth: Art of Byzantium from Greek Collections," scheduled to open Sunday, Oct. 6.

"The show includes some of the most stellar works from the Byzantine era," Ziska told A.i.A. by phone Wednesday. "It was the first time ever that a lot of these objects were to be seen in Washington. We have many Greek officials here, including the prime minister, and they were locked out of the preview."

The museum had already extended the exhibition "Diaghilev and the Ballets Russes, 1909-1929: When Art Danced with Music."

"The Diaghilev show was supposed to close in September, but we extended it to Oct. 6," Ziska said. "It has been very popular, totaling about 225,000 visitors, and this is the show's only venue. We can't extend it any more. So if we don't open by Sunday, many people will miss out."

The National Gallery receives about 12,000 visitors a day on average in the fall, Ziska said. In the week of Sept. 23-29, the Diaghilev show alone had an average daily attendance of about 1,600-more than 13 percent of visitors. "It would have been more this week since people knew it was closing and were coming in from out of town," she added.

Ziska, coincidentally, recalls that she was greeted with a shutdown on her first day on the job, as acting head of the press office, in November 1995.

The Smithsonian has many museums, devoted to many fields, not only art. "We were expecting to get a T. Rex from Omaha that was to go on view Oct. 16," St. Thomas said.

Other cultural institutions are seeing a marked rise in attendance.

"It's much more crowded here today," said Mimi Carter, spokesperson at the Corcoran Gallery of Art, which is privately financed. "I would estimate we have five to 10 times as many people as we have on a usual fall Wednesday. There are typically 17 museums plus all the monuments available for visitors to the city. The Corcoran becomes a real cultural icon when all of those places aren't open."

Ironically, one of the Corcoran's current exhibitions is the New York-based artist Ellen Harvey's "The Alien's Guide to the Ruins of Washington, D.C."(through Oct. 6), which the museum's website describes as "a glimpse into a distant future in which aliens, enamored of classical architecture, have turned the uninhabited Earth into a prime tourist destination."

The exhibition includes a printed guide to the ruins of Washington, D.C.