The first ladies' gowns -- scheduled to go off exhibit in the Smithsonian's National Museum of American History here after Labor Day -- may go to Dallas to be displayed for as long as a year.

The gowns, together with the Hope diamond and Charles Lindbergh's airplane Spirit of St. Louis, have been the most visited objects in the Smithsonian Institution. Meanwhile, protests about closing the popular attraction and especially about transporting the fragile, historic gowns are beginning.

"It's like prostituting the first ladies' gowns, sending them out on the street to raise money," said Margaret Klapthor, curator emeritus of the National Museum of American History. "The Smithsonian has always turned down requests for the dresses to travel. They're far too fragile. Why, it takes half a day just to undress one, and twice as long to dress it. I don't think the dresses should be taken off the mannequins at all."

Roger Kennedy, director of the History Museum, said, "I don't know if there will be a tour of first ladies' gowns." But he added it's "a suggestion which logically could be made."

John Crain, director of the Dallas (Tex.) Historical Society, said: "We understand that a loan is a possibility. Though we can't anticipate what the Smithsonian will do. I hope to hear something by October." The Dallas society is hoping to borrow (and pay a considerable fee for the privilege) at least some of the gowns for an exhibition to open its new Hall of State in 1988-89, Crain said.

Kennedy said he's trying to get a large donation to reinstall the First Ladies Hall. "The precise date depends on the arrival of good news. We are trying for a large donation of money from a private source to help pay for the conservation of the dresses.

"The cost could go to half a million. We won't know how much until we get the costumes off the mannequins and look at the undersides."

He would not say where this money was expected to come from. But he did say he hopes to reinstall the first ladies' gowns eventually "in a new setting. They'll be a part of a complete redo of the presidential collections, including the gowns, the White House china and furniture. It will be installed on the second floor of the museum in as large and handsome a space as they now occupy. The first ladies won't be cramped as long as I'm around." The new hall could cost at least a million dollars, "but we haven't costed it out yet," Kennedy said. "About $1.4 million would speed things up.

"If we had to wait for a congressional appropriation and the Office of Management and Budget, or to be fitted into the Smithsonian's overall budget, it would take longer than I want to wait. That's why we're looking for private funding. The ladies should get back on public view as soon as possible."

"The Texas loan is only a preliminary proposal at this time. We're exploring ways to pay for the conservation," said Marilyn Lyons, American History Museum director of external affairs. "I have sent out letters to a select group of corporations asking for donations, but I haven't called them yet."

A new exhibit area is to be built for the 44 dresses and the 750 or so furnishings -- including two pianos, accessories, china and jewelry used in the White House.

Meanwhile, the oldest dresses will be taken off exhibit for a yet unknown length of time to be conserved while their present location is prepared for another exhibition. The dresses of the six living first ladies will remain in their Red Room setting, at least for now.

Klapthor planned the current exhibit and oversaw the First Ladies Hall from 1943, when it was in the Arts and Industries Building, through its move to the Museum of American History, and until her retirement in 1983.

Kennedy said not everyone is equally impressed with the collection. "the dresses are a big yawn to high-style academics," he said.

Klapthor retorted, "They're not high-fashion, but an American history collection. They weren't the most fashionable dresses of the year. Some of the women who wore them were sick, or not interested in fashion or society. These were simply their best dress."

Dallas' Crain said he had "been made aware that the gowns hall was coming down. And our board asked questions about them being available for tour ... We don't know how many are in a condition to travel ... The price we'd pay would be subject to negotiation. You could say we're testing the waters.