To an adult, it looks like a formless mound of gray clay, but to the eight-to-12-year-olds in Lorna Williams' pottery class, there are monsters in the mound -- and unicorns and lions and swans and other creatures waiting to be liberated by eager young hands.

And while those young hands are up to their elbows in clay, three- and four-year-olds in the next room are coating lemon halves with paint and stamping their images on paper. The five-to-seven-year-old set, meanwhile, is deciding what kind of masks to make for Halloween.

It's all part of the daily activity at the Captiol Hill Arts Workshop. This weekend the non-profit school for the arts is inviting the public to a celebration marking the group's renovation of its headquarters in the old B.B. Ffrench School at Seventh and G Streets SE. Saturday from 1 to 2:30 kids of all ages can try potting, printing and mask-making at the workshop -- for free.

"I may bring my potter's wheel and let them try it," says William, a British journalist who turned to professional pottery when she had children and wanted to work at home. "But in class we don't use the wheel because it's very frustrating until you learn how to center. With hand-building, there's immediate satisfaction. You can make something each time. It's a wonderful way of getting used to clay. You use the palm of your hands and your thumb almost as if they were a potter's wheel."

For a warm-up, Williams has the kids make pinch pots.

"It's sort of like playing scales on the piano," she explains, showing the students how to take two balls of clay and roll them between the hands until they're exactly the same size. Then the balls are hollowed out and placed one on top of the other and carefully pinched together.

"But it's going to burst in the kiln," protests Nancy Kaufmann.

"No, because we're going to put a hole in it," Williams reassures her, wielding a small tool that looks like a needle on a stick. When the hole is pierced, Nancy puts a straw into it and blows gently.

"Can you feel the pot expanding?" asks Williams. "You should be able to . . . Look up a minute at Annabelle's. It has a nice round shape."

After smoothing the pot with water, Annabelle Pitkin takes another lump of clay and starts working on what she really had in mind all the time -- a unicorn.All the kids, according to Williams, have their own things.

"Teddy read a book on Mexican face pots last summer, so he does a lot of those. They're almost like Toby mugs," she says, holding up Teddy Crowell's latest smiling mug." And Brad likes to do fat, mythical animals." c

"They're monsters," corrects Brad Chrisholm, twisting the tongue of a dragon to make it appropriately pointy.

Cici Borth has already finished her dragon, pointy spine and all, and is pounding out a flat slab to place on it.

"We learned last year that animals with long tails nearly always got broken unless we put them on something," explains Williams.

Laren Spirer is avoiding the tail problem by making only the head and neck of the Loch Ness monster. After delineating Nessie's eyes, Laren hollows out the neck.

"If you don't hollow it out it would take ages to dry," explains Williams. "And in the kiln air pockets might make it blow up.

As the hour draws to a close, the kids start worrying about things not yet done, like bears without arms, dragons without wings and sailboats without masts.

"I don't think you have room for three masts," Williams advises Rosemary Pitkin, who summers in Maine and allows the "next time I want to make a lobster boat."

Nancy Kaufmann puts her trumpeter swan in a plastic bag "because I want to put a tail on next week," and Cici Borth wraps her unfinished lion. Rachel Canning's mouse is ready for the kiln, although Williams is worried about the creature's long, long tail. Duke Harjo presents Williams with his creation: c"a volcano with insides."

"Oh, I can see, yes. Very intriguing," she says diplomatically.

When the stray clay is scrapped off the table and every piece of artwork is initialed and ready for firing, Williams has a minute to talk about kids and pottery.

"Kids are so keen, so imaginative, that you can't stop them," she says. "When I first starting teaching, I thought I'd have to constantly think up projects. But they know what they want to do. All I do is show them a few techincal tricks."