A few hours before this week's Monday and Thursday matinees, the blue unit of the Ringling Brothers and Barnum & Bailey Circus was holding its own informal circus in the center ring-auditions for showgirls Monday, and on Thursday for clown college, Ringling's tuition-free eight-week training school in Venice, Fla.

A dozen would-be showgirls and 40 potential clowns turned up-proof that there are still people who want to run away with the circus, work as many as 13 shows a week for 46 weeks, never have a Sunday or Saturday off, and live on a train.

"Are you interested in a job right way?" circus choreographer Jerry Fries asked the tall slender woman who had just auditioned for circus showgirl-a job of dancing, parading and riding some animals.

"yes, definitely," Lisa Brightman said. Her eyes were intent, her expression sober. She is 19, with fluffy light red hair, flawless skin and an attractive sprinkle of freckles. She wore tights, a leotard, and a T-shirt that said "How'd You like a Big Wet One?" She quickly followed the dance steps that Fries demonstrated.

Lisa Brightman quit Walter Johnson High School in Bethesda after her junior year. She models now. "I want to be in show business," she said. "If I can't, I'll be a wife. I figure I've got 10 years till I hit My prime. This is a good start. It's definitely a foot in the door. And it's better than sitting in the audience watching. Who knows-maybe I'll learn an aerial act."

Gil Wadsworth, 19, mimed getting stuck in a phone booth for his audition in the center ring, surrounded by other auditioning candidates and the deans of the clown college, Ron and Sandy Severini. When he was a kid, Wadsworth said, he would pantomime at home. When his parents asked him at night if he'd brushed his teeth, he would suck his cheeks in and pretend he was brushing vigorously with a toothbrush.

His father only encouraged this behaviour. Seated at the dinner table, when his mother wasn't looking, his father would catch young Gil's attention and pretend he was sewing his lips together or pulling his thumb off.

It was fun, and a way of getting around the boy's speech impediment-he stuttered. Since then, Gil Wadsworth has studied mime for several years.

Wadsworth, a sophomore at Towson State College from Cockeyesville, Md., would quit tomorrow if he got a job with the circus, he said. He saw the circus six times in Baltimore last month and auditioned. He's seen it three times here in the last two weeks. If he does not get into Ringling's clown college he will go to Rochesterr, N.Y., the next stop for the circus, and audition there again.

"The idea is to show them I'm interested," he said. "And I like following the circus around."

Some of the clowns now with the circus stumbled into the auditions to watch, coach applicants, and just clown around.

"Anybody here 4-foot-3?" asks a little man in a plaid suit as he struts through the ring.

He was born Daniel Rodgers, but he's now known as the Tasmanian Dwarf Devil. He is 4-foot-3 and he's been with circus for three years. "Why not?" The world was getting too tall for me."

Rodgers is 23, with blond hair aand a strong smile that does not look silly despite the clown makeup. He wears two earrings in one pierced ear.

A few years ago he was an accounting major at a Dallas junior college-for one semester. He then took odd jobs a a welder, an assistant veterinarian, and-perhaps for the gag value -as crewman on a shrimp boat.

Travelling around Texas, he ran across the circus, and decided to apply. He went to Los Angeles for an audition. He had never even seen a circus performance. "I said, 'Hey, I'm a short guy. Give me a job. I'll be a clown.' That was the first thing I said."

He got the job. "I love what I do," he said. "I never liked working before."

His parents love it too. "They can't believe I've finally found steady work," Rodgers said.

Elizabeth Foley, 25, has a bachelor's degree in Spanish and Portuguese from the University of Maryland. She worked for two years for the U.S. embassy in Brazil as a research technician.

But now she was sitting in a leotard after auditioning as a circus showgirl. The choreographer said he may be interested in hiring her.

But she's undecided. Her mother and friends are horrified. And she has just been told she will have to learn to do aerial ballet hanging by her wrists and ankles near the top of a 27-foot rope. She was assured the circus teaches slowly and carefully. Even so, she glanced up across the vast space of the arena and grimaced a little.

"I really enjoy dancing and I think this would be fun," said Foley, a gymnast in college. "But how is it going to look to future employers? Wouldn't you worry if you took time off to do something different and then went back and you had this thing on your resume-'joining the circus?'"

Ringling clown Michael Brevig was discussing unicycles with clowncollege hopeful Jack Tobin.

"Known what a wind-up is?" asked Brevig. He hopped on his six-foot Schwinn unicycle and did some quick spins in place.

Tobin, 20, came from Northhampton, Mass., to audition. He juggled and rode his own unicycle.

"Joining the circus is not as far-fetched as some people think," he said. Tobin drives a forklift for a brick company sometimes. During his one-semester stint in school he spent his time in the library reading magic books.

"It's the same as trying to become a chemist or anything else," he said. People say to me, 'what are you gonna fall back on? What are you gonna do if it doesn't work?'"

He shrugged and laughed a little. "I don't know. What the heck? What is anyone gonna do if whatever else they've got falls through?" CAPTION: Picture 1, Circus showgirls tryout Lisa Brightman above, by Harry Naltchayan.; Picture 2, At right Ann Holmes gets some clown makeup help from Ringling's Peggy King, left, and Steve Harris, center, by Ken Feil-The Washington Post