SOMETHING LITTLE this way comes.

The Howard Bros. Circus is playing an extended engagement in Explorer's Hall at National Geographic Society headquarters. It's the greatest little show on earth, collected from the four corners of the globe by Howard Tibbals, a parquet-flooring manufacturer from Oneida, Tennessee, who just happens to love the circus.

Though this circus is only one-sixteenth life size, we're talking Big -- over a million parts. About 4,000 people in street clothes -- Tibbals calls them "towners" -- are flocking to the Big Top to watch the Flying Wallendas, the lion act, the trained seals and the human statues. To laugh at Emmet Kelly. To hear the band, 26 figures hand-carved by Tibbals, who copied their postures from church elders during boring sermons. And to see the red-caped horsemen on parade, their faces looking distinctly like LBJ's.

The 1930 Howard Bros. Circus rolled into town about two months ago, and it's taken that long to set up. (It has, count 'em, 7,000 folding chairs.) The circus was stored in box cars that were emptied in the same order as for an old Ringling Bros., Barnum and Bailey.

The Big Top and the Menagerie tents were unfurled and tied down. For the dining tent, 8,000 dishes and 850 place settings of dollhouse silverware were unpacked. Out came the steam tables for the tiny corn on the cob in the food preparation tent, and kewpie dolls and Crackerjacks for sale on the Midway. And the sideshow signs that light up at "night," advertising "Mo-Lay, Master of Manipulation" and "Skeets Hubbard, Human Pin Cushion." Out came flocks of fantastic feathered hats for the Dressing Tent.

Now, inside the Dressing Tent at the performers' stations, a clown may be seen washing his armpits while tiny Barbie dolls apply their stage makeup. Water buckets and trunks bear real performers' names, which Tibbals gleaned from annual circus "route books."

He adheres to a degree of historical accuracy understood by only about 400 people -- the estimated number of serious "circus modelers." Take, for example, No. 202 wagon, the ticket booth. It is thoroughly finished to the smallest detail inside -- and only its maker, opening its doors with tweezers, will ever get close enough to see the little slots for the different colored tickets. In the Menagerie -- which, Tibbals is quick to remind, was the only way most Americans saw zoo creatures -- he even built an air- conditioned wagon for Gargantua the Great. It was the only way to keep that big gorilla.

Spending nights and weekends of the past 30 years on the project, Tibbals has consulted circus performers and workers, old photographs and old circus posters. What he calls his "circusana" collection is legion. In the exhibit, a hundred posters (a mere sampling) recall spine-tingling days: "The most startling discovery of the century -- Giraffe Neck Women from Burma" and "The Seven Wonders -- The Hirsute Sisters," seven beauties with hair down to their feet and then some.

Although Tibbals may attend a dozen circus performances a year, it was the circus he didn't see that got him started. At age eight, he was visiting his grandparents in Fairmont, West Virginia, when the circus came to town. His grandfather, who worked on the railroad, took him to see the circus train unloading. But his grandparents wouldn't let him go to the actual circus. So, with binoculars, he watched its comings and goings from a neighbor's front porch.

He thought of joining the circus. What he really wanted to do was not to balance on the high wire but superintend the circus lot. He's gotten his wish at the National Geographic.

Anyway, the real circus doesn't suit him any more. "The circus today," says Tibbals, "is nothing but a smelly ice show."