It used to be that at Prince William County Fair the big attraction was men wrestling men. Nowadays, its machines battling machines.

The big event, the tractor pull, is only one of hundreds of ways to part with your dimes and dollars as traditional harvest-time country fairs begin this weekend in Maryland and Virginia.

The tractors, as they are loosely defined, are massive, low-slung, chrome and steel, glaringly polished monsters with names like Lickety-Split, Big Red and Foolish Pleasure. What they are pulling is a weight-transfer machine, or a sledge, called Sitting Bull. The tractors weigh perhaps 1,200 pounds at the most. Sitting Bull weighs 45,000 pounds, with the weight increasing as the tractor pulls forward, trying to go the distance -- 300 yards -- in a soft dirt pit.

The noise is so shockingly loud it makes your diaphragm vibrate. Fumes from gasoline and oil envelope the crowd as the machines leap forward in their 30-second bid against Sitting Bull. Dust and dirt from the pit flies up behind the wheels, and the smell of burning rubber hangs hard and acrid in the air.

"Farmers have always been extremely competitive," said Bill Clem, who announces dozens of tractor pulls all over the East Coast, and will MC the one in Prince William County this Saturday night and Sunday afternoon and evening.

"They are also very good mechanics and spend hours on these tractors. This is the equivalent of drag racing."

Usually billed as "old-fashioned fun," county and state agricultural fairs have become increasingly slick in recent years with elaborate carnivals and merchants' displays.

Despite the commercialism, country fairs are still fun, and Prince William County's should be no exception this year. It's very much an old-fashioned fair with large livestock barns, active Future Farmers of American and 4-H participation, flower and vegetable competitions, food preservation judging, baking contests, baby and twin competitions and continuous displays all day. Nights are lit by carnival lights swirling and flashing, and resound with the sounds of Country & Western music, bluegrass and gospel songs form a large stage flanked with grandstand seats. There will be pony shows, horse shows, goat and dairy cow judging, a beauty contest and a midway roaring with race cars every night.

In addition to rides and sights, the food is made in heaven for the junk-meal freak. Country fairs are known for what they call barbecue -- a hamburger roll topped with hot and spicy shredded pork or beef, swimming in juicy sauce and, where health laws permit, covered with slaw. Be warned that, if you never had one, the country fair barbecue is addictive. You also can get something called fried dough, which tastes far better than it sounds. It's essentially batter, tossed into piping hot oil and allowed to turn a golden color before it's quickly removed, drained on a napkin and topped with powdered sugar. Then there are sausage sandwiches, barbecued chicken, Sluprees and lemonade, and the list goes on and on.

Prince George's County will also hold its fair this weekend. But the two biggest local fairs are the state fairs -- Maryland's, in the elaborate fairgrounds at Timonium, complete with a brand-new chandeliered cattle barn; and Virginia's, in mid-September at the state capital. Further information is available from county extension agents and state tourist bureaus.