For a good time, call 785-1777 and ask for Eleanor.

Or if you're in the neighborhood of lower Dupont Circle, just drop in between noon and 8 p.m. at the Red-Light Museum and Gift Shop, where Eleanor Valentine (who sometimes wears an enticing turn-of-the-century costume) will make you welcome with a friendly smile and a cup of coffee or iced tea. Eleanor is the manager of the newest, smallest and most unusual museum in a city of museums: two rooms devoted to the history of erotica and particularly of the oldest profession -- love for sale.

Streetwalkers can pick out the museum (located at 1819B M St., NW) easily -- it's the building that has the two painted ladies (actually painted on plywood) leaning out of second-story windows, resting their generous bosoms on the windowsills and smiling an invitation to passersby. It is upstairs, over King Arthur's, where the ladies don't even wear paint, and across the street from the Mirage message parlor. The museum's owner, Dennis Sobin, Ph.D., thinks it is ideally located but can see the time coming when it will need more space.

What it offers right now, three weeks after starting up and some time before the official grand opening, includes a small but choice selection of 19th-century photographs, daguerreotypes and lithographs of ladies of the evening, blown-up newspaper clippings of 1915 vintage about the outlawing bordellos, copies of old police reports, a velvet-covered love seat where you can sit and watch a slide show of Victorian-era erotica, and a 1913 map of the District of Columbia giving the location of the red-light districts -- which tended to cluster near the White House and Capitol Hill. d

Washington was a flourishing center of the venerable profession as soon as it became the nation's capital, according to Sobin, and particularly during the Civil War -- about the time the term "hooker" was invented in honor of General Joseph Hooker, who was better known as a patron of the city's fancy houses than as a defender of its perimeters.

"Washington is an ideal city for this kind of establishment," he says. "It is a great city for museums, and the adult trade is excellent here, partly because it is an international tourist market. A foreigner can come in and understand everything here -- love is a universal language. Last week, we had a customer who didn't speak a word of English, but he didn't need to. He wanted to buy a few things, and I just wrote down the prices."

In a lunch-hour crowd one day last week, four men were walking past the museum and glanced up at its unusual front. "Have you been in there?" one man asked another. "You can get anything you want in there for $10." He was not strictly accurate. Like all museums these days, the Red Light Museum has a boutique, but the prices range from 60 cents for a French postcard to $80 for a large, framed reproduction of a hand-painted 19th-century daguerreotype, whose post-card size original would cost about $4,500. One fast-moving item is "The Erotic Guitar," a recording of background music with occasional sounds of human moaning and panting, which sells for 99 cents if the purchaser presents a newspaper ad offering the discount.

The stock includes reproductions of classic erotic sculptures, paintings (a Gauguin, for example), colored posters made from old Vogue covers, films, casettes and photographs as well as books, magazines and the kind of mechanical apparatus usually found in adult bookstores. On the wall are signs in 19th-century typefaces: "Commit No Nuisance. This is a Clean and Orderly Establishment. Scoundrels Will Be Dealt With Severely," or "Sailors Registering with Street Girls Must Pay for Room in Advance." A free copy of one of the signs is offered with each purchase.

Eventually, Sobin expects the boutique to meet the expenses of the museum, which charges no admission fee and offers free refreshments to visitors. "Only about 5 percent of the people who come in buy anything," he says. "But there is a lot of repeat trade, and our customers are mostly affluent people. Most of the men who come in here are wearing a jacket and tie and have money in their pockets. It's so noticeable that someone asked me a few days ago if we have a dress code. We have quite a few women coming in, too. They usually won't buy anything here, but they take our catalogue and order things later by mail."

Before starting the museum, Sobin says, he spent about six months doing research at such places as the Smithsonian, the Library of Congress and the National Archives, which have supplied information or materials for the museum's exhibits. "We also contacted the LBJ Collection in Texas, because it is the repository for the material collected by the President's Commission on Obscenity and Pornography, which includes a lot of classic pornographic material. They were happy to send us copies -- their only worry was whether it would be carried by the Postal Service."

The museum is an offshoot of TAB Report, a newsletter Sobin publishes for people in what is called The Adult Business: shops that sell erotica, producers of films and cassettes, massage parlors and other publishers. The newsletter has about 400 subscribers.

The museum was planned primarily as a public-relations showcase for the adult trade, according to Sobin, who has a doctorate in sociology from New York University and worked for years as a teacher and consultant in that field, while writing occasional articles for various erotic publications under a pen name. "I decided to come out of the closet as a heterosexual with TAB a couple of years ago," he says. "It doesn't pay as well as sociology, but I enjoy it more and it gives me access to a lot of interesting people."