I SPOTTED WASHINGTON'S genius loci one day, in Georgetown. I was driving around gathering details for a novel I was writing, called "Fool's Mercy," and I saw her. It should have come as no surprise that the genius loci was a woman. Like most cities, Washington is a feminine entity. (Ankara, Turkey, is a conspicuous exception, as are Pueblo, Colo., and Naha, Okinawa.)

The genius loci is what I'm always looking for when I travel, even when I'm traveling in my home town, which has been Washington longer than any other home town I can remember. It's the spirit of a place, the minor deity which gives it the essence you remember after all the lectures and guidebooks and American Express bills are forgotten. It can reside anywhere, and it can only be glimpsed, never stared at like a monument or a cathedral.

Riding on a train through the more impoverished areas of Southern Italy, for instance, a friend of mine turned from the window with that look that means the elusive genius loci has been seen. He said: "All those cement mixers." And certainly they seemed to sum up the slow, aspiring grind of life along the tracks. I realized I had seen it in Edmonton, Alberta, one March day when, with a fever coming on, I began to suspect that the people of that strange, bleak city either move only their eyes and never their heads when they glance to one side, or they move only their heads and never their eyes, I wasn't sure which. In any case I remember that particular genius loci as having the aspect of some kind of stoic lizard in a down jacket. And telling the same joke over and over: "Edmonton weather? Eleven months of snow and one month of bad sledding, eh?"

Anyhow, Georgetown was a strange place to be seeing the genius loci of Washington. Then again, it was August. Georgetown, to my way of thinking, doesn't count as Washington except in August when a considerable proportion of its citizens seem to escape to the New England seacoast, depending on European exchange rates. To me Georgetown is bogus and artificial, full of people who leave their outdoor gas lamps burning all day, and call the back door the tradesman's entrance, a locution they advertise on polished brass plaques. Georgetown makes me think of women pushing baby carriages they're apt to call prams, the sort of sight that makes you look into the carriage to see if there's a baby in there at all.

So I drove into Georgetown one August morning, not in search of the genius loci of Washington, but only to savor the flavor of the place, toward which the upper-middle-class desperado lovers of my novel were steering at that point in the writing. Trees sagged in the heat, sunlight bounced off Volvo windshields in smeary glares, as I would later write. (Why not lift a phrase or two from your own work?) Georgetown seemed like something rendered useless by August, like a wool jacket with the pockets full of mothballs. Then I saw her, standing on one of those front porches that no one ever sits on, since they kicked the poor folks out of Georgetown. She was deeply tanned, a particular shade of Anglo-Saxon ruddy. She was wearing a denim skirt. She was the kind of woman who has never felt quite comfortable on a beach since bathing suits with little skirts went out of style. She was sorting mail with a certain scornful impatience, and I wondered to myself: Is she just back from the Vineyard for a funeral? Her husband's nervous breakdown?

To me she embodied all the dowdiness and resentment that are required attributes in Washington. Hot. Nervous. Dressed with a Puritan spareness that passes for informality here. Living in a house vastly smaller than what her husband's income would buy her in that mythical land Washingtonians call "back home." Rootless. She didn't want to be here, she couldn't go anywhere else--a Washingtonian. And totally ordinary, the kind of sight that can only be seen out of the corner of your eye: the genius.

This sort of vision is, for me, exactly what touring--and a lot of fiction writing--are all about. So I rode and walked and jogged around all the scenes of my book in search of glimpses. I'd had plenty of practice, fortunately, having done most of my previous traveling dirt poor, when I couldn't afford many of the great sights. I lacked money, and often energy. Contrary to popular youthful opinion, it is not possible to switch to a diet of bread and cheese and roar around Paris seeing and loving all of it. The same equation holds true for Rome and spaghetti al burro, Tokyo and soba (a popular soup) or Pakistan and the flat bread called chapatties. Nor does Athens look any better after you sell a pint of your blood to buy more moussaka.

But there is always plenty of time. The hard-up traveler spends a lot of time sitting and standing around, waiting for a ride, a money order, or a surge of enthusiasm. It is very ordinary. It is life as we live it most of the time at home, in fact. The difference is in the glimpses. Spend enough time sitting on the ground at what is said to be a bus stop in Zahedan, Iran, and after a while you will notice the guy next to you is playing a tiny three-stringed instrument that looks like a bass fiddle the size of a porringer. Wander a few doors down from the bus stop and watch the baking of bread by men who reach down through a hole in the top of the oven and slap a handful of dough onto the oven's ceiling, seizing it off moments later just before it plummets into the flames below. You have plenty of time at the bus stop in Zahedan. I had five days, and then somebody told me about a train that I took.

You get the point. The idea is to look around as if you're looking for something to write home about when there's nothing to write home about, this being particularly difficult when you're already home, here in Washington. Maybe this is one reason I wrote the novel. In any case, there's plenty to glimpse, to make mental notes on--backgrounds and scenery for the novel you've always known was in you.

I left out the monuments, except for a mention of the Washington one with those two little red lights at the top that make it look like a cross-eyed, winking, hung-over planarian yearning to launch itself into the night sky. And I included a late-night drive along the Mall, with "Abraham Lincoln brooding over the pre-dawn marble emptiness."

But that's it, basically, for anyplace that the tour buses stop.

For me, the monuments and the great restaurants of any country exist as arbitrary goals, and on the way to them you see what's really important. Go to the Taj Mahal, sure, but take a night train to get there, and on the way stay up and notice the fact that no matter how late the hour or how rural the scene, with the fields shining in the moonlight, you can always see people walking around--genii loci of a country which has as a defining fact a population of half a billion people.

In Istanbul, the Santa Sofia mosque is as good a place as any to see one of the porters who hauls huge weights around the ancient city on his back. One of them I saw was carrying two coffins at once, moving along with a tread good for a million miles. There's a genius, all right.

They're everywhere, if you just look for them.

Some people hope to find them in the more exotic monuments, in which this city abounds, such as the pet cemetery in Wheaton where J. Edgar Hoover's dogs are buried, or the Mighty Midget kitchen on the way to Leesburg, or the house on Cleveland Street in Takoma Park where Goldie Hawn grew up, or Bonfield's gas station on MacArthur Boulevard, a simulacrum of every 1930s social realist rural gas station you ever saw, with a clientele so well established that Mr. Bonfield had his own rationing system during gas shortages--he only sold it to his friends. And let's not forget the strange and ancient "parade" as they call it, in the basement of the Masonic memorial to George Washington in Alexandria--the parade being a huge mechanical procession of horses and soldiers and so on, the martial equivalent of a model railroad.

None of these are in my novel. Nor are there seafood restaurants, for which Washington is unjustly famous, or cherry blossoms for which the fame is deserved. In fact there are no restaurants at all, this being a startling lack for a novel set in a town where the upwardly mobile seem to spend all their time talking about the restaurants they went to last week when they're not talking about the eccentricities of their cleaning ladies. And there are no cherry blossoms because my book is set in that most quintessential of Washington months, August.

If you're looking for quintessence, you go to Paris in April, New York in autumn, and Washington in August. August is the time of that sick, itchy heat when the sky turns gray brown with smog and it won't rain, and the setting sun burns like napalm over Rosslyn, the whole city defeated by it, slumped into an embarrassed, funereal hush.

Tourists can stare at the Jefferson Memorial or the Smithsonian's collection of dentists' chairs as long as they want, and never understand this. But if they rode along Florida Avenue in the mammoth, roasting twilight, they might see the genius loci in the persons of three little black girls doing a time step together, perfect unison out on the sidewalk, step, step, step, clap. Even stranger, by virtue of being so ordinary that you'd never think of looking at it as a tourist unless you were writing a novel, is a drive out funky old New Hampshire Avenue, in the Maryland suburbs, in the windless heat, an August evening that implies the seasons have surrendered, that's it's going to be August for the rest of time. Lawn sprinklers twitch in quick gleams like the glintings of golf clubs at a driving range. A pickup truck goes past full of kids holding bathing suits in the wind like flags, jolting away into the dirty rose haze. It's beautiful, because if you catch it right it illuminates something, beauty being truth and all that. You have to throw away your preconceptions about beauty, of course--this the only way you ever see the genius.

A turn here and there, and you'll come to my town of Stuckey. It isn't hard to find. You've probably been there one time or another, and call it by some other name. It's the mean-dog and used-motorcycle capital of the world, full of men who are proud to stand up when they work and women who like to turn the lights out when they make love. They paint their mailboxes red, white and blue. They have a lot of handgun accidents. They go to church with hangovers and black eyes. Washington gleams not far away but they don't know what this country is coming to, and still think it's unfashionable to use four-letter words at the dinner table.

These are genii of Washington too, much as Georgetown may call them rednecks or ignore them completely if they're black. If it sounds like I prefer Stuckey to Georgetown, it's because I do, whether I find it off New Hampshire Avenue or in Virginia, or out MacArthur Boulevard. There's a particular beauty to all the Stuckeys scattered across this country that the compulsive and competitive gentility of the Georgetowns can never duplicate. Then again, I'm a man who once spent a winter vacation in Paterson, N.J.

Laugh, if you want, but you've never seen the mural at the Italian-American Sporting Club, or the incredible falls, which may be somewhat smaller than Niagara, but are far yellower. In all seriousness, I will argue for eternity for the beauties of the north end of the Jersey Turnpike, with the scaffolding traceries of the refineries and gas flares twitching and the sun sliding over the oil tanks, acres and acres of them, wrapped with little spiral stairs.

The closest we can come to that glory in Washington is New York Avenue, with all the trucks and the no-tell motels. My characters wander out there too, so I followed them, discovering that on the south side of the avenue, in back of a couple of those motels, trucks from North Carolina and other country places park, and cars, all kinds of cars, from junkers to Lincolns, gather around them late at night to buy watermelons. And these people know watermelons. They heft them, they rap on them, they argue about them, and then they take them home with odd looks of triumph on their faces, genii loci all of them.

These are the things that you have to live here to understand, unless you're a very astute tourist indeed. They are Washington.

Don't even get me started on the bus station, with the bum shaving himself with a naked razor blade, and the Amish in black standing next to the pimps in purple . . . or Connecticut Avenue on a hot night, with the old masonry facades and chanceries and shrouding trees that remind you of Paris, and it's so quiet you can hear the stoplights clicking when they change, and when you drive out on that long stretch of bridge over Rock Creek Park you feel dwarfed and exposed, as if you were the only human left alive in the city; as if, for a sweet moment, you had become the genius yourself.