Window on a fascinating world

For the Yupik Eskimo dancers, the Washington Mall was the hottest gig they'd ever played. There they were, singing and drumming and shaking up a storm in their wolverine hats, leather mukluks, wolf-fur parkas, bird feather bonnets, and fans trimmed with caribou fur.

The dances were sizzlers, for the temperature that day was in the humid, sweltering 90s. Alaska was the spotlight at this 18th annual Festival of American Folklife, which is why these native dancers were in subtropical Washington doing their walrus, owl, seal, and mosquito dances, with accompanying masks.

Their performance was an example of how the tricky business of showcasing a people - in the diversity, richness, and inimitable style of its folkways - can be accomplished. If done well, the showcase can sometimes be a window on a fascinating world.

And that's exactly what happened at this festival. Sprawling and multifaceted , the event strove to catch the spirit of a people and its customs in a variety of ways - despite challenges like dancing in this climate. When the Bethel, Alaska, dancers (who are Yupik Eskimos) left the stage to hearty but moist applause, their spokesmen explained how tough it is: ''For anyone from Alaska, it is really a problem to keep from keeling over,'' said spokesman and ''presenter'' George Charles. ''We drink a lot of stuff, water and Gatorade, but it's trying for the elders.''

In Bethel, he said, the median winter temperature is 40 to 50 degrees below zero, and it goes down to 70 below with the wind-chill factor.

The Smithsonian Institution, which sponsored the festival, lured the Yupik Eskimos down to Washington at the height of the fishing season, in which they make their living. ''So they gave up a lot to come down here,'' Mr. Charles said. ''For most of the elders, who have never traveled, this is a totally new world to them.''

Also included in this year's festival were sections devoted to the urban dance, music, and cooking traditions of black Philadelphians and to the ''heritage-bearing role of the elderly.'' But the most exotic section was the Alaskan, where visitors wandered through striped tents and talked to people like Eva Heffle, an Inupiaq Eskimo from Kotzebue. She's a dollmaker who lives 35 miles above the Arctic Circle and makes dog-sled dolls, sewing up the stiff furs with dental floss instead of the caribou tendon that many Eskimo women use as thread.

There was also Tlingit Indian Esther Littlefield, a Sitka bead worker who lives part-time in the Washington area teaching at the National Park Service. She sat behind a vivid array of garments decorated with seed beads, including one of her own tribal family emblems, a frog worked in green beads with blue eyes.

Cindy Herpst of Skagway stood in front of a stack of sourdough pancakes made from family ''starter'' and talked about sourdough secrets: ''Keep your start fresh and full of action, let it ferment . . . the batter should look velvety and full of holes. The hotcakes should be light and sweet.''

One of the most popular exhibits was the gold-panning display, which was acrawl with kids watching mud sluice down a wooden waterway to tubs where they could search for tiny nuggets. Another hit with the kids was a huge, pale blue hunk of Alaskan glacier ice. The size of a large breadbox and extremely dense, it was slow melting, with lots of tiny bubbles visible through its mirrorlike surface.

Over in the Philadelphia section, you could have stopped to watch tap dancer Levaughn Robinson, dubbed ''the man with the machine-gun feet'' when he toured five African nations recently.

A few tents away, the William Carson family and Mr. Carson's aunt, Arlena Davis, were fixing soul food, including collard greens, chicken, candied yams, biscuits, and sweet potato pie. The sweet potato pie sold at a nearby food both was one of the hits of the festival: cold and spicy, with bits of orange sweet potato in a creamy filling with flaky crust. ''Blacks in the city do not eat a lot of sweet potatoes in the summertime, that is our winter dish. But the Smithsonian people requested us to do sweet potato pie,'' explained Patricia Carson. Then Arlena Davis passed around a pan of golden biscuits she'd just whupped up.

That's the way it was at the folklife festival, where you could have polished off the day savoring Robert Burghardt's delightful mural, ''Growing Up in New York City.''