Correction: The byline on last week's Daylife was incorrectly spelled. J. B. McCraw wrote the "Commodious Guide to Mall." We regret the error. (Published 6/29/90)

WASHINGTON is a great place to visit, but I wouldn't want to go to the bathroom there. Over 15 million people a year visit the nation's capital, but the public buildings have woefully inadequate bathrooms. Public toilets at the tourists meccas on the Mall are hard to find, too small and often dirty. As a tour guide who has watched many visitors search for bathrooms, I offer a guide to the best and worst bathrooms in the Washington that visitors see. I call it the Loo Tour.

National Park Service rangers say that the most frequently asked question in the District is "Where's the bathroom?" Visitors are forced to ask because federal officials do not like to mar the appearance of the federal enclave with toilet signs. An observant visitor should look for the longest line in the building, monument or memorial. That's usually the bathroom. The Loo Tour, however, will help you avoid those long lines.

I rank the Mall's bathrooms by stars, with one star being a place to avoid and four being a must-see. The best bathrooms are accessible, clean, spacious, and well-stocked with paper and soap. Civilized bathrooms do not have hand blow-dryers, but, unfortunately, most public bathrooms do. THE LOO TOUR

1/2

THE CAPITOL --

Don't go to the bathroom in the Capitol. The Founding Fathers did not provide for women in the Constitution or in the Capitol's bathrooms. A woman did not sit in Congress until just before our country entered World War I, and no woman should ever sit in the tiny toilets in the corridors next to the Crypt. (The men's room near the gift shop also has only two stalls.) Make a pit stop at the Supreme Court or the Library of Congress across the street before you visit the Capitol for your free tour.

If nature calls while in the Capitol, ride the subway in the basement to either a Senate or a House office building. Ask a Congressional aide for the closest bathroom. Hill aides are easy to spot. They are the smug-looking recent college graduates. They look smug because they don't have to use a public toilet.

SUPREME COURT --

The bathrooms are clean, small and easy to find. Enter the basement level, Maryland Avenue side. Walk straight ahead toward the humongous seated statue of Justice John Marshall. Take a peek at the amazing cantilevered marble spiral staircase directly across from the women's room.

LIBRARY OF CONGRESS, JEFFERSON BUILDING --

Even though you are allowed to see only two books in the public part of this 80 million-volume library, the bathrooms are worth seeing for their old-fashioned charm. Go through the revolving doors on the ground floor, past the sales shop and the screening room with the film about the history of the Library. The large restrooms are outfitted with oak veneer stalls and cabinets enclosing the lavatories, cool white and clay red marble, and graceful hanging light fixtures. You can put your feet up and relax in the anteroom. BYOB (Bring your own book).

1/2 BOTANIC GARDENS --

To find an oasis away from the madding crowd, walk downhill from the Capitol to beautiful Victorian greenhouses. Go through the orchids and the tropical forest, past the desert, and you're there. The peacock-blue bathrooms are never crowded (except at Christmastime), but they are always out of paper and soap.

AIR AND SPACE --

This is the world's most visited museum, with an average of 6,000 visitors an hour during high season. Avoid these small bathrooms because they are totally inadequate to accommodate the crowds. On an average Sunday, 70 women are on line at any one time for the first-floor bathroom, according to a guard stationed nearby. Every half-hour, 450 people leave the movie theater with the IMAX screen and head for the bathrooms. Check the movie schedule so you'll know when not to go. Once, I saw a desperate mother of two offer a $10 bribe to a woman at the head of the line.

If you can't wait, make a beeline for the Flight Line Cafeteria, down a long corridor on the east side. Make an immediate right as you leave the museum. There are two modern, clean, one-stall handicapped bathrooms. If you visit on a weekday morning, the bathrooms in the museum are not as crowded and are thus cleaner. The stalls do have nice bright red doors, and two of the hand dryers are at a child's height.

NATIONAL GALLERY OF ART, WEST --

Like the building -- a classical temple to art -- the bathrooms are clean and elegant. Also, the daily number of visitors is in the hundreds, not the thousands, according to guards. You have several convenient bathrooms from which to choose, but begin with the pair behind Mercury in the Rotunda. His raised right winged foot points you in the right direction. Take a left for the women's or a right for the men's after you pass the gigantic Ionic columns. This women's restroom has a roomy sitting room with one bench; the men's has the space but no furniture. The subdued lighting and somber walls are very soothing. You will find everything you need, from tissue seat covers to plenty of coat hooks, so you don't have to dump all your belongings on the floor.

Since the East Wing has only two cramped bathrooms, make a last stop here before you take the people-mover to the newer building. On the west side of the museum, take the down escalator, stop on the landing to admire Dali's "Last Supper," continue down. Pass the sales shop on your left and walk left to the telephones, across from the Cascade Cafeteria. These modern restrooms with recessed lighting have the same color scheme as the two East Wing bathrooms -- white and aqua.

NATIONAL GALLERY OF ART, EAST --

The minuscule bathrooms are on the concourse (on your left as you debark from the people-mover) and upper levels. Warning: If you are on the upper level close to the Calder mobile, you cannot go directly to the bathroom on that level. You have to go down a level, cross to the cafeteria escalator, and up a floor to the left. We have I. M. Pei, the architect, to thank for this.

NATURAL HISTORY --

This museum, opened in 1910, has one of the worst bathrooms on the Mall, but it also has one that's not too bad. Avoid the bathrooms behind the African bush elephant next to the sales shop. You have to go down narrow, steep steps, and sometimes it smells like a dead mastodon. To reach the decent bathrooms, enter the museum on the Mall side, go through the Ice Age on the left, and turn right at the walrus. The bathrooms on the ground level, Constitution Avenue side, are rather pleasant. The women's room has a sitting room, many stalls and curiously, one hand dryer on a pedestal in the middle of the floor, like a parking meter.

AMERICAN HISTORY --

Skip the dirty, smelly puce-colored bathrooms on the lower level between the cafeteria and the sales shop. Look for the clean ones that flank the Palm Court, the delightful old-fashioned ice cream parlor. Enter on Constitution Avenue, walk dead ahead through the Material World exhibit and, in the lounge dotted with wicker furniture, look overhead right and left for the charming oval green signs that mark the bathrooms. The Mall-level bathrooms, to the right of the Foucault Pendulum, are pretty gross but have a plaque on "Bathrooms in America" that is interesting.

HIRSHHORN --

This contemporary art museum has only one pair of bathrooms, but what bathrooms! A minimalist's dream, they each have one of the best wheelchair-accessible stalls in the city. The facilities have their own lavatory and sitting-level mirror. If the bathrooms had paper towels, they would be perfect. The museum entrance, a revolving door, is on the Independence Avenue side. But to get down to the lower level where the bathrooms are, visitors in wheelchairs should enter on the Mall side. Tap on the glass double doors and a guard or attendant at the adjacent information desk will let you in.

AFRICAN ART AND SACKLER --

Because these galleries are only about two and a half years old, they have modern, pleasant facilities. Take the elevator down to the restroom level, which is marked on the elevator. The womb-like bathrooms have water fountains, telephones and even a contemporary wall clock, the kind with hands but no numbers. The Sackler is cleaner than the African, probably because fewer children venture into the Asian collection.

ARTS AND INDUSTRIES --

The bathrooms in the oldest museum on the Mall would deserve four stars if they were easier to find. Ask at the information desk. The friendly volunteers are accustomed to giving the complex directions. Beware of the misleading, large "WOMEN" sign hanging from the balcony next to the sales shop on the left if you come in on the Mall side. The sign indicates a display of books written by women, not the bathroom. The volunteers say that women almost walk through the wall trying to find a restroom there.

WASHINGTON MONUMENT --

Go before you queue up for the elevator to the top, because you could be on line for an hour or more. There are two sets of bathrooms on the Monument grounds -- one awful and one bearable. Pass by the one connected to the snack bar on 15th Street, the first stop of every Tourmobile passenger. These bathrooms are monumentally gross by noon. The restrooms on the north side of the Sylvan Theater -- in a round, clean building -- are utilitarian, but never have soap or towels.

JEFFERSON MEMORIAL --

These bathrooms would be as good as you can get away from home, if they had towels. They are clean, spacious, with a nice anteroom for changing the baby or having a nice sit-down. Enter on the ground level on the west side, next to the sales shop.

LINCOLN MEMORIAL/VIETNAM VETERANS MEMORIAL --

These bathrooms are government issue, that is, they are designed like the ones at the Jefferson, but what a difference! Barely adequate before the Wall began to attract people in unprecedented numbers, the situation is now hopeless. Imagine a coliseum toilet after a rock concert, and you get the picture. Rumors abound that the Park Service will replace the information kiosk near the Vietnam Veterans Memorial with a larger building that will include restrooms, but it may be a while. To find the bathrooms in the Lincoln take the left sidewalk to a ground-level room that houses the bathrooms and a photographic display of the building of the Memorial. Be sure to check out the stalactites.

? WHITE HOUSE --

You may wait in line an hour or more for your tour, but you cannot go to the bathroom in the president's mansion. If the urge strikes while strolling with the masses, a Secret Service agent politely escorts you around the throng, out the front, and points you to Lafayette Park (and the restrooms in a small stucco building near St. John's Church), or to the Old Ebbitt Grill next to the Treasury Building on 15th Street. There's also a restroom kiosk on the Commerce Building side of the Ellipse near where the tour line forms. When asked why visitors cannot go to the bathroom on the tour, the White House Media Relations Office issued this statement:

"This is a historic monument that averages 4,000 visitors a day. We would have to reconstruct the building and build more facilities in order to let the public use the bathroom in the White House."

Read their lips -- no new bathrooms. Also, a media relations staffer said, "We have our security interests."

J. B. McGraw, a writer and tour guide, frequently points the way to comfort stations on the beaten path in Washington.