Open Mondays through Fridays from 11 a.m. to 1:30 a.m. Saturdays from 1 p.m. to 1:30 a.m., closed Sundays. Street parking. Accessible by wheelchair. American Express, Amoco Torch Club, Diners Club, Master Charge. Reservations not necessary.

During the marvelously gregarious lifetime of restaurateur William W. (Billy) Simpson, who died two years ago, you could never be really sure just why each of the many customers showed up - for they had so many reasons.

Some came merely for the famous Southern cooking, some to fill up on a diet of stimulating conversation about politics, sports, social problems or humorous happenings, and still others simply to revel in the informal combination of it all.

But there on Georgia Avenue N.W. Billy Simpson's House of Seafood and Steaks was a unique gathering place, a haven for people of all races in the days when this was a heavily segregated town. At Billy's you were treated not as a customer but as a guest.

So it took a moment or two to adjust on a recent Saturday evening when three of us found the restaurant nearly empty. Still, with our two hungry children in my charge on this occasion I wasn't about to let this suprise throw us off. When there's good food, kids don't need a crowd to egg them on anyway.

For that matter, the quiet proved to be delightfully contagious at our table. A good hush, as parents know, can reduce ear-splitting observations from offspring to an audible flow of pleasant, even informative, chatter.

When the children are hungry, though, food for thought becomes a side dish. And in this instances, there so many other courses to be charted on the impressive menu, so many difficult choices between favourite dishes.

In an admirable if unnoticed exercise of self-restraint, I bypassed all sorts of enticing items on the appetizer list in favor of chicken soup at 95 cents. Those with more abandon and less girth could begin with shrimp cocktail at $2.95, crabmeat cocktail at $3.25, New Orleans gumbo at $1.10, or with that old consolation prize - fruit cup - at $1.25.

Chicken soups do vary, but this one hit all the right taste buds, including those of my two culinary consultants.

Then it was on to the main attractions, which run the range from daily stick-to-the-ribs specials such as beef tidbits and boodles, all undeer $4, to seafood, soul food and beef.

From all this, my 8 year old daughter chose a dish exotically entitled Delicious Fried Chicken, for $4.85. It was aptly dubbed, she reported, and as a dyed-in-the-feathers chicken afficianado, she ought to know.

In making his selection, my 10 year old son recognized the steaks involved and avoided the high ones. Though I duly warned him that "chopped sirloin steak" can be a restaurant's euphemism for hockey-puck hamburgers, he had more faith.

Naturally, my fatherly tip was entirely off the mark. His charbroiled steak at $5.25 was sizeable, rare and, like the generous platter under the wing of his sister, came with great amounts of lettuce, cole slaw, tomato, rolls and other fillers.

To top it off, he had ordered a $1 helping of fried onion rings, the bulk of which were to wind up in a doggie bag for later.

A chicken-fried shrimp platter, my choice at $5.45, was entirely satisfying. And for those who can't make up their minds easily, there's seafood enbrochette - lobster tail, shrimp, scallops, filet of fish, mushroom butter, rice pilaf and a vegetable for $6.95 - or surf and turf (lobster tail and steak) for $10.50.

Other selections include chitterlings with homemade potato salad for $6.95, pigs' feet with potato salad and greens for $4.95 or, for the undecided again, a combination of the two for $5.95.

Stand-bys for the younger set include ham or roast beef sandwiches with French fries at $1.50 each or, for $2.95, a hot roast beef sandwich with mashed potatoes. In salads, there's everything from a $1 version to a $4.65 tomato stuffed with crabmeat salad.

Speaking of things stuffed, the children - having conquered most of their mountainous offerings - neither needed nor requested dessert. Our total bill was $19.45 plus tip.

By the time we were bunding onion rings for our exit, it looked as if more people might be trickling in for an after 9 dinner. We hoped so, at least, for this longtime, "second home" of Billy Simpson had upheld his tradition of fine cooking.