The Howard County Fair begins Sunday and continues through next Saturday. The starting date was omitted from yesterday's Weekend section.

As numbered Ping-Pong balls float on an air current in a box before her, a woman croons, "B-36, B-36. I-75, I-75, N-20, N-20 . . ." The sun is going down behind the 4-H barns.

A bearded man sits in a swing attached to a scale. Weighing in at 225, he'll guess your age, says the sign, within two years, your weight within three pounds, and your first name.

"Is it Layla?" he asks a little girl who shakes her head, picks up her prize circus glass and walks away in disgust.

"They're going to have to change that sign," he mutters. "I can't guess first names. Kids' names are weird!"

The carnival nights are here, following days jam-packed like Mason jars full of stringbeans.

The season of the county fair has begun.

The big state fairs -- Virginia, Maryland, West Virginia -- are expected to entertain between a quarter and a half a million people apiece, and some county fairs nearby -- Montgomery and Frederick, for example -- are in the same league, judging from last year's attendance.

About a fourth of the people who went to the State Fair of Virginia last year went to eat, says J. Linwood Rice, public-relations man, citing a survey. "Can you believe it? To eat?" he asks.

Well, yes. There's always a barbecued chicken to be had, washed down with Mr. Pibb and followed briskly by corndogs, candied apples, funnelcakes and cotton candy.

But how can you concentrate on food at a fair -- when, from a trapeze on a helicopter, a man is hanging by a toe? When cars in the Thrill Show squeal by on two wheels and crash head-on?

When there are greased-pig scrambles? When there are tobacco-spitting, cow-chip-throwing, hog-calling, horse- pulling, log-sawing, chicken-flying and worm-crawling contests? Not to mention beauty contests, baby contests and cute dog contests where dog and owner enter as a team? "That's right," says Rice. "Sometimes they even look alike."

County fairs are nostalgic places, where memories are stirred by the hot breath of the hay, the clang of the horseshoe toss and the animals' constant cooing, crowing and mooing. But mixed in is the new. The commercial exhibits are as likely as not to have a Jacuzzi as centerpiece, near the booth of the Humane Society, which is next to the Izaak Walton League's display of stuffed animals.

Raised lovingly by 4-Hers, the livestock are docile garden varieties. But there are less-known breeds, too: coon mules that jump hurdles as horses do, fancy breeds of chickens bred for feathery legs -- "Not the chicken you'd fry in your kitchen," explains Helen Hance of the Calvert County Fair, which will have a large poultry exhibit -- but the kind of chicken that's black, white and reddish orange and lays green eggs.

And if these pleasures aren't sufficient, there's the carnival man, who glues black tape over his sign where it says he'll guess your first name and who's quickly running out of straw hats and beer glasses, because he isn't any good at guessing weight, either. FAIRS OF STATE, AND COUNTY MARYLAND AUGUST 20: Howard County Fair, West Friendship. Out Georgia Avenue to Route 144, turn right to the fairgrounds. Hours: Sunday, noon to 10, weekdays, 9 a.m. to 10 p.m., August 19-20, 9 a.m. to 11:30 p.m. Admission $2 for age 12 and over. Phone: 301/442-1022.

Midway, daily horse shows, local country-western groups, household crafts, pit-barbecued beef, commercial exhibits. Sunday, horse & carriage parade, chicken-flying contest, hog-calling contest, milking contest, farm queen contest, fireworks. August 20, baby contest, worm-crawling contest, horse-pulling contest, pretty animal contest. AUUGUST 22 -- 27: Montgomery County Fair, Gaithersburg, off I-270. Hours 7 a.m. to 11 p.m. Admission, $3; age 12 to 15, $2; under 12, free. Parking, $2. Phone: 926-3100 or 963-3247, fair week.

Midway, 4-H demonstrations, Old McDonald's Farm, food preparation demos (shucking, meat-cutting, breadmaking), pretty cow and goat contests, livestock shows and sales. Evening of August 22, unlimited midway rides for $6. August 26, demolition derby. August 27, antique tractor pull contest, children's story hour, U.S. Navy Band (Country Current), The Hollanders, mud wrestling. AUGUST 27 -- SEPTEMBER 7: Maryland State Fair, at the State Fairgrounds, Timonium. Off I-83 north, exit 17. Hours 10 to 10 for exhibit halls; 12 to 11 for midway. Admission, $2; with thoroughbred racing, $3. Parking, $1. Phone: 301/252-0200.

Midway, livestock show (sheep, swine, cows, goats), horse shows, lamb-shearing demos, home arts (sewing, baking, gardening), micro- mini tractor pulls, drafthorse pulling contest. Thoroughbred racing: post time, Monday to Friday, 3; Saturday, Sunday and Labor Day, 1. Entertainment: daily, Louise (pop country). August 27, Shore Patrol (rock group). August 27, 28, September 3, 4, Son of a Gun (bluegrass). August 27, 28, September 1, 3, 4, Mirage Professional Dancers of the Middle East. August 28, Kangaroo Kids (precision jumproping). September 2-5, Frisbee demos. September 5, Wrangler country showdown (country music contest). SEPTEMBER 8 -- 11: Prince George's County Fair, county equestrian center, Upper Marlboro. At U.S. 301 and Route 4. Hours 11 to 10. Admission $3; $1.50 age 7 to 12; $1 age 55 and over. September 8 only, 18 and under, 50 cents. Parking, $1. Phone: 952-0270.

Midway, hot-air balloon rides, pony rides, livestock, daily scarecrow workshop, continuous musical entertainment on the weekend. September 9, horsepulling contest, firefighter's brigade competition. September 10, tractor pull, swine sale. September 11, 4-H horse show. SEPTEMBER 15 -- 18: Charles County Fair. Off U.S. 301, three miles south of LaPlata. Hours: September 15, 5 to 9, September 16-17, 9 to 9, September 18, 10 to 6. Phone: 301/934-9240.

Farm museum, daily dog show, 4-H, carnival. September 16, talent show. September 17, baby show, 4-H horse show, horse pull. September 18, horse pull, local choral group. SEPTEMBER 19 -- 24: The Great Frederick Fair, East Patrick Street, Frederick. Take the first Frederick exit on I-270 and follow signs to the fairgrounds. Hours 10 to 10. Admission $2; under 10, free. Parking, $1.50. Phone: 301/663-5895.

Additional charges for these events: September 20-23, for sulky races and musical entertainment, afternoon grandstand admission, $1. Evening events, prices ranging from $3 to$10; September 19, tractor pull. September 20, Chicago Knockers (women's mudwrestling team). September 21, Statler Brothers. September 22, Demolition Derby. September 23, Sylvia. September 24, afternoon, Joey Chitwood's Thrill Show (hell drivers); and evening, Mickey Gilley. SEPTEMBER 21 -- 25: Anne Arundel County Fair, Sandy Point State Park. On U.S. 50 just before the Bay Bridge. Admission $2, 11 and over; senior citizens with I.D., $1.50; $1 for age 6-10; under 6 free. Hours: September 21, 4 to 11; September 22, 1 to 11; September 23, 4 to 11; September 24, 8 a.m. to 11 p.m.; September 25, 8 to 7. Phone: 261-1703, ext. 6755, toll-free, or 301/757-3311.

Midway, 4-H exhibits, poultry-judging contest, swine show, beef show, draft horse pull, car driving contest. September 23, cattle show, Country Fun Band. September 24, baby contest, 4-H demos, amateur talent show, livestock auction, Stone Mountain Bluegrass Boys, fireworks. September 25, Country Current, children's tractor pull, square dancing demos, dog obedience show, Gazze (rock group). September 24 and 25, horse show, horseshoe pitching and flea market. SEPTEMBER 22 -- 25: St. Mary's County Fair, St. Mary's County Fairgrounds. On Maryland Route 5, two miles south of Leonardtown. Hours: September 22, noon to 9; September 23 and 24, 9 a.m. to 10 p.m.; September 25, 8 to 6. Phone: 301/475-9388 or 301/475-5694 during fair days.

Carnival, pony rides, home arts, chickens, rabbits, barbecued chicken and beef. September 23, 4-H horse show, horse pull, Navy Band. September 24, jousting tournament, horse pullm, the Hollanders. September 25, open class horse show, weaving demonstrations, baby show. SEPTEMBER 29 -- OCTOBER 2: Calvert County Fair, Prince Frederick. Take Route 4 to Prince Frederick; turn left on Dares Beach Road. Go 1/2 mile. Hours: September 29, 4 to 11; 9 a.m. to 11 p.m. other days. Phone: 301/586-0523.

Horse pulling contests, tractor pulls, 4-H and commercial booths, large poultry exhibit, livestock, barbecued fresh pork, crabcakes. September 30, Little Miss contest, Sour Mash (country music). October 1, horse and pony show, Hot Ice Band, children's pet show, fashion show, country music. October 2, Country Comfort Band, horseshoe pitching contest, gospel singers. VIRGINIA THIS FRIDAY & SATURDAY: Warren County Agricultural & Industrial Fair, six miles outside of Front Royal. Take I-66 to U.S. 522 north, to fairgrounds about four miles up on the right. Admission $3. Phone: 703/635-5719.

Catch the tail end of it today -- exhibit buildings open at 6 p.m. Evening highlights: Steve Wariner (country music), kids' and womens' greased-pig contests.

Saturday, gates open at 2 for the baby beef and livestock sale. Rides on the midway start at 6, followed by Razzie Bailey (country music), and the men's greased-hog contest. THIS FRIDAY -- AUGUST 20: Prince William County Fair. From I-66, on Route 234 south of Manassas. Hours: Noon to 11 weekdays, later on weekends. Admission includes all rides and shows: $5 for ages 3 through 59; $3 age 60 and over. Phone: 703/368-0173.

Tractor pulls, home-arts demos, baby, beauty and pet contests. Evening entertainment: Friday, Fifties Night with the Coasters and the Orions. Saturday, disco. Sunday, Miss Prince William County Fair pageant. Monday, dairy judging. Tuesday, bluegrass. Wednesday, wrestling. Thursday, auto thrill show. August 19, talent show. August 20, country music. AUGUST 21 -- 27: Page Valley Agricultural & Industrial Fair, Luray. Take I-66 to the Front Royal exit. South on U.S. 340. Left on U.S 211 business (East Main) and follow signs. Admission $2; age 6 to 12, $1. Hours: 6 p.m. to midnight. Phone: 703/743-5240.

Midway. Livestock shows and sales. August 21, opens at 1, horse show, baby contest, Page Valley High School Band, beauty contest. Most exhibits open August 22. August 26, demolition derby. August 27, drag races. AUGUST 22 -- 27: Clark County Fair, Berryville. Take I-66 west to U.S. 50 to Route 340 north to Berryville. Go a mile west on Route 7 to fairgrounds. Adults $2; 15 and under, $1; pre-school free. Hours: 10 to 10. Phone: 703/955-1131.

Livestock, home arts, horticulture, carnival. August 26, horse and pony show, battle of the bands, beef & chicken barbecue. August 27, western show, tractor pull, greased pig scrambles, beef & chicken barbecue. AUGUST 25 -- 28: Arlington County Fair, Thomas Jefferson Community Center, 3501 Second Street South. Free admission. Hours: August 25, 7 to 10; August 26-27, 10 to 9; August 28, noon to 6. Phone: 558-2475.

Basically an indoor fair, with 4-H exhibits, commercial booths, petting animals, rides, balloons, food, games, local band music. AUGUST 28 -- SEPTEMBER 3: Shenandoah County Fair, Woodstock. Take I-66 west to I-81. South on I-81 to exit 72. Hours: noon to midnight. Admission, $2 adults; children 8 to 12, $1.50 starting August 31. Harness racing, August 31 to September 3 at 2 p.m., grandstand admission, $1. Parking, $1; some free parking available. Phone: 703/459-3867.

Midway, livestock, poultry show. August 28, horse show, fiddle and banjo contest. September 2, Reba McEntire. September 3, Steve Wariner. SEPTEMBER 1 -- 10: Fredericksburg Agricultural Fair. Take I-95 south to first Fredericksburg exit. Turn left on U.S. 17; pass through business district to fairgrounds. Hours: weekdays, 5 to midnight; weekends, noon to 1 a.m. Admission $4; children under 12 free. Parking $1. Phone: 703/373-1294, fair days.

Carnival, livestock, home arts, beauty pageant, baby contest, tractor pull. September 3-4, horse show. SEPTEMBER 22 -- OCTOBER 2: State Fair of Virginia, Richmond.m Take I-95 south to Richmond and follow signs as you reach the northeast city limits. Hours: 8 a.m. to midnight. Admission, $6.95, covers all carnival rides and events. Phone: 804/329-4437.

Draft horse pulling contest, tractor pulls, horse shows, cute dog contest, tobacco-spitting contest, ice-skating show (daily), circus, the Great Rock'n'Roll Time Machine (pictures and recordings), thrill show, nightly concerts. Carnival. Home arts, lamb shearing contests, sheep dog trials, precision tractor driving, log sawing and chopping, dog show, fancy breed poultry show, poetry contest. WEST VIRGINIA AUGUST 19 -- 27: West Virginia State Fair, Fairlea. Take I-66 west to I-81. Go south to I-64, then west on I-64 to the Lewisburg exit. Take Route 219 south two miles to Fairlea. Hours, 8 a.m. to midnight. Admission, $3; children 12 and under free. August 19, $6 admission includes all rides and shows. Concert prices other days range from $5 to $10. Phone: 304/645-1090.

Harness racing, horse shows, champion livestock auction, draft horse pulling contest, 4-H demonstrations, local entertainers, West Virginia crafts. Free circus. Midway. August 19, Wrangler Country Showdown (talent contest); Earl Thomas Conley, Sonny James, Hot Ice. August 20, Statler Brothers. August 21, Bobbie Vinton. August 22, Myron Floren. August 23, T.G. Sheppard. August 24, The Beach Boys. August 25, The Lettermen. August 26, Mickey Gilley and Janie Fricke. August 27, Charlie Daniels Band.