Bob Berry has been clowning around for years. If he could, he'd love to be a full-time clown and tour the country.

So every spring when the circus comes to town, the Takoma Park man auditions for the clown school run by Ringling Brothers and Barnum & Bailey.

Berry tried again last week. Wearing a droopy felt hat, a bulbous nose, blue and white makeup and a melancholy expression, the 31-year-old high school media specialist sashayed around the circus ring performing his "Diamond Collection" mime routine.

The "gag," as it is called, involves a large diamond-shaped piece of glass, which Berry rubs enthusiastically while swinging a black suitcase that seems to hold the promise of more "diamonds." When the suitcase pops open, the diamonds turn out to be playing cards of the diamond suit.

Berry, who took a course in clowning at Montgomery College and who calls himself "Tooti the Clown," also juggles and does sight gags--"things the circus uses a lot," he says.

He has wanted to be a circus clown "forever," he says, and for the fourth time in four years, he took time off from his job with Montgomery County public schools to audition. Afterward he was asked to remain for an interview, but there was no certainty he would be selected. Only 60 out of 5,000 applicants are chosen each year.

The auditions, held throughout the country, are open to anyone willing to, as the Cole Porter song puts it, "Be a clown . . . act the fool" for a couple of hours.

Berry was one of 23 men and women who auditioned for Ron and Sandy Severini, the deans of Clown College, which is located at the circus' winter quarters in Venice, Fla. Looking on were a dozen circus clowns, including Tom Parish, a "boss" who supervises 26 clowns, two of them female.

The auditions were held at the Baltimore Civic Center, where the circus, billed as "The Greatest Show on Earth," was performing last week.

Stretched high above the traditional three rings were the wires, nets, ladders, ropes, poles and rigging used by high-wire and trapeze artists. Parked nearby was the "Rocket Car," from which some hardy optimist is shot during each performance. A mildly pungent animal odor, without which no circus would be complete, added a touch of realism.

Working out in the center ring, adjacent to the one being used for the clown auditions, were members of the King Charles Troupe, a group of young basketball unicyclists from New York City, who whooped and hollered through their rehearsal.

Several auditioners were asked to pretend to be inanimate objects--an alarm clock about to go off, a popcorn machine about to heat up, an electric toothbrush about to be plugged in and a hand-held hair dryer with a "big motor."

Severini also asked applicants to do double takes and falls, walk an imaginary tightrope, bite into an imaginary apple with a worm in it, make funny faces, look scared and "be happy, happier than you have ever been before."

One of the hopefuls was 19-year-old Mary Ann Moeller of Laurel, who has completed her first year of pre-med studies at the University of Maryland at Baltimore. She said she is taking the year off from school to work as a free-lance clown. She began performing as a clown in 11th grade, she said.

"I am serious about this," said the 5-foot-5-inch, blue-eyed blond. "When I was little I used to threaten my parents that I was going to run off with the circus and be a clown." Now, she says, "My parents are really pleased . . . since I am going to carry out my original plan to join the circus--if I can get in."

Moeller, who does a "little" juggling, says that when she performs she wears a blue and red costume, balloons and ruffles, a red yarn wig, white makeup with blue stars around her eyes and a painted smile. She has worked as a camp counselor for the Laurel Department of Parks and Recreation and has performed with the department's Gingerbread Players.

She said she wants to be a clown "because I love the anticipation of going out there in front of everybody and doing what you want to do. It's worth it because you make people happy--that's the greatest, the ultimate."

Although she says her school friends want her to "pursue my medical studies," Moeller said she would rather "visit the sick as a clown and not have to deal with life-and-death situations. I could make sick people happy," she said. "Everybody loves clowns."

As did all of the tryouts, Moeller and Berry performed their own routines as well as circus routines, pantomimes and improvisations. They were coached by Severini and the clowns, who also performed for the group.

Even if Berry or Moeller made it to Clown College, there is no guarantee they would land a job with the circus. Severini says that usually about half of the 60 persons who complete the college's specialized tuition-free 10-week course will be hired by the circus, depending on the number of openings.

Clowns must serve a three-year apprenticeship. A spokesman for the American Guild of Variety Artists, the union for circus performers, says that they earn "between $250 and $350 per week," or more if they can negotiate a higher fee.

Tammy Parish, 23, the "boss clown's" wife, says "money is not the reason why people work here," although she said she and her husband "have managed to save more than we could any other way." She said they live on the circus train year-round, as do all the performers. Their home base, she said, is the circus' winter quarters in Florida.

"It's a hard life, not 8 a.m. to 5 p.m.," Tammy Parish said. "You start at 8 a.m., but you work until midnight. You work for the circus 24 hours a day and are on the road 11 months out of the year."

Parish said she and her husband, who have been married for three years, "have a mutual feeling about clowning" and plan to make the circus their career. They grew up together in Kansas and began dating in junior college, where they were art students.

Severini, who was born and reared in Irvington, N.J., and who auditioned for the circus at Madison Square Garden in New York City in 1971, urged people to come to auditions "to find out what clowning is all about, because there is no other feeling like it in the entire world."

After 10 weeks of training, Severini said, "a person can make it to the top of his profession, working with top circus professionals from around the world."

It is not necessary to audition to apply to the college, Severini said. He said applications must be received by the Clown College, P.O. Box 1528, Venice, Fla., 33595, no later than July 15.

Berry said he plans to audition again when the circus performs in Washington. The Washington auditions will be held April 13 at 10:30 a.m. at the D.C. Armory Starplex.

Moeller, who was not asked to remain for an interview, also plans to try again. "I am going to give it another try in Washington. First of all, I didn't know what to expect," she said. "This was a lot more fun than theatrical auditions, where you get a number and are told to do this or to do that and thank you. This was a lot more personal. They call you by name, work with you, answer your questions. It leaves you with a feeling that you can always try again."