The little tent pitched on the lawn at Encanto Park is quickly filling up with noisy children who have dragged their parents to yet another circus. It's getting crowded and hot, but the kids seem only to notice that the Center Ring is so close they can almost touch it. The predictable canned circus music is blaring from the back of a truck poking into the tent. Inside the ring, a motherly-looking woman in denim coveralls and remarkably heavy make-up is giving pony rides for a buck apiece. Suddenly, she and ponies disappear. Inexplicably, the orchestra swings into a bluesy version of "Kansas City." The Ringmaster bounds in, dressed in a red cutaway embroidered with red-sequin stars. He booms a welcome for "Miss Heidi Wendany and her Hollywood Doggy Revuuuuue!"

Miss Heidi--my God, the pony woman--prances into the ring and no matter how many circuses you've been dragged to, you're not quite ready for this. Her Rubenesque form is now encased in a startling, shiny red stretch jumpsuit. She's wearing see-through plastic spike heels. The lights bounce off her matching rhinestone choker and ankle bracelet. Her Hollywood Doggies burst into the ring and it takes but a moment to recognize they're a half-dozen mutts she's rescued from the dog pound.

But today they're having their fifteen minutes of fame as Miss Heidi snappily presents each hound executing improbable canine stunts. This one rolls a barrel with his front paws; that one climbs a ladder using all fours; the smallest balances between two ladders. Her panting devotees run dizzily between props garnished with gaily colored feathers. All the while Miss Heidi vamps like the star of an Andy Warhol movie.

Finally she retakes center stage and opens her arms triumphantly as the last pooch completes its trick more or less successfully and rejoins its distracted companions in more or less a straight line. The audience roars back in delight.

Those old enough to recognize high camp are helpless with laughter. But the considerable number of children who dominate this audience sees it for exactly what it is--good old-fashioned entertainment. For them it matters not that the "orchestra" is a pair of retired nightclub musicians enjoying a second childhood or that the props are decorated with common household feather dusters.

It is opening week of the 1990 tour of the combined Culpepper & Merriweather Circus, Arizona's very own real live (not to mention "Magnificent, Moral and Stupendous") circus, ladeez and gentlemen.

RINGMASTER Robert "Red" Johnson grew up loving old-fashioned tent circuses long before life swept him into the direct path of one. And when the opportunity finally came to start his own six years ago, he vowed to create a circus connected to its sawdust-and-canvas roots--something he says the huge, Las Vegas-influenced shows lost the moment they moved indoors.

So if the first few shows of this year's tour seemed just a leetle loose, the stagehands so clumsy they seemed to be wearing shoes one size too big, no matter. The tour sailed majestically forward, buoyed by the enthusiasm of fans who are young enough to understand what's important here: Plenty of animal acts, stars who are friendly to persons shorter than themselves, and the freedom to scoot forward on their bellies until their noses nearly touch the ring--these are the true measures of circus greatness.

And judging from the reception among young fans, this year seems destined to vindicate Robert Johnson's faith. "Mom, can we go again?" "I want to meet Miss Heidi and her dogs." "Geez, the best part was . . . "

As for adults, welllll, the Culpepper & Merriweather Circus isn't P.T. Barnum's idea of the Greatest Show on Earth. But it could well be the funniest. Only part of its comic appeal is intentional and you're never sure if they know the difference. Did they really not notice that the blue-velvet noose used by the aerialist would be perversely humorous to anyone who's seen the twisted cult movie Blue Velvet? Was it just thriftiness that prompted them to try disguising a collapsible laundry hamper, embellished with metallic letters, as a stage prop? But the most delicious moments come when fate's devilish hand tugs a feather loose here or a string there to confound the best-laid plans. Whether by design or accident, the undercurrent throughout the show is hilarious camp. It's almost as if the crew of a tramp steamer woke up one morning and decided to run away and join the circus or, failing that, had started its own. And then hired Warhol with his peculiar perspective on American culture to be artistic director.

The Culpepper & Merriweather Circus, in short, is the perfect prescription for a city stewing in recessionary gloom.

THE TOUR LAUNCHED in late February from its winter quarters in Buckeye--there is no kinder way to put this--had its share of rough spots.