The aroma of chicken frying in 350-degree lard could be smelled for a quarter mile around today, but in the midday heat at the 150th annual Clarksville Picnic, it was Jennie Thompson's icy cucumber slices that kept folks returning for seconds.

"Yessir, we've had eight bushels soaking in vinegar since last night," said Thompson, who has whipped up the picnic's giant batches of pickled cucumbers for the past 35 years. This year, she and friends worked hours to prepare enough of the paper-thin slices for the more than 3,000 people, who paid $5.50 each for the all-you-can-eat affair.

Like most country fairs, Clarksville's--which has been sponsored by St. Louis Catholic Church since 1878--is a time for young and old alike to renew friendships and family ties, to exchange a quiet word with the parish priest and to savor some of the finest home cooking this side of the Patuxent River.

Although it attracts outlanders from Virginia, Delaware and beyond, the picnic has yet to lose its "down home" flavor, according to residents of this Howard County town, 20 miles north of Washington.

"The best thing about it are the families and the volunteers," said Thompson, 64, who lives two miles from the fair site on Rte. 108. "I've got seven children and they're all working here today. So are 12 of my 19 grandchildren."

The picnic was first started by Howard's corn, dairy and horse farmers, who gathered every August--except for two years during World War II--to celebrate the coming of the harvest. In 1959, however, the pastor of St. Louis moved the picnic date to the last Saturday in June.

"In all these years we've been rained out only once, and then during tropical storm Agnes," said Herb Martin of Simpsonville, who has been coming to the picnic for 20 years and for a decade overseeing the preparation of the five-hour dinner. "I guess we let the Lord rain after 6 p.m. He always holds off 'til then."

Today's weather was picnic perfect: clear skies, puffy white clouds and a crisp breeze that snapped the giant tent shielding the diners. And the food was even better: 3,000 pounds of chicken fried to a turn in five large vats, 500 pounds of country ham from Westminster, Md., 650 pounds of succotash made with sweet corn, homemade apple sauce and fresh beets. Tucked in one corner of the 15-acres of church property was a staggering and highly caloric array of baked goods, including brownies, tarts, fudge, cakes and muffins.

"It used to be that we had to beg for volunteers to help fix the food, set up the picnic," said Buzz Wiedel, a Dayton, Md., resident who has managed the chicken frying for seven years. "Now everybody wants to pitch in. It's a community thing, with a lot of families." Wiedel, 59, had eight relatives preparing food--his wife, Martha, two sons, a daughter, their spouses and assorted grandchildren.

Elizabeth Westendorf, who drove a busload of 40 parishioners from Holy Trinity Church in Glen Burnie to the fair, said, "Where we come from you don't have things like this, and when I get back I'm going to spread the word about the picnic.