I have waited on the edge of a mesa at sunrise and first heard the dry, flat sounds from the desert tortoise shells tied to the legs of the dancers as they rise from the shadowed plain below. -- Nathaniel A. Owings, architect and Kachina doll collector

Nothing can substitute for the experience of actual presence -- with the smells, sounds and sights -- as masked and costumed Kachinas, embodying ancient spirits, enter a Hopi Indian village to perform a cycle of elaborate and sacred rituals.

The next best thing to a mesa sunrise as an introduction to the Hopi way of life is a visit to the Smithsonian's National Museum of Natural History/National Museum of Man. "Hopi Kachina: Spirit of Life," an exhibit on the culture of Arizona's Hopi Indians, continues through Jan. 3.

It is an exhibit that engages the senses to help one experience and understand the Hopi way of life. At the hatchway of kiva -- an underground ceremonial chamber -- you hear the sounds of Kachina dancers practicing songs for their appearance at public dances. More than 150 Kachina dolls are arrayed for ceremonial rituals in two large, scale-model pueblos. Two continuous slide shows capture the strong faces of the Hopi Indians as they speak today of the past and future.

Huge photo-murals show Kachina dancers in ceremonial finery at the turn of the century before the Hopi barred cameras from their sacred rituals. And the murals capture the harsh beauty of the arid, windswept mesas and farmlands of the Hopi Indians' villages of northeastern Arizona.

In Hopi religion, Kachinas are supernatural messengers who mediate between the harsh realities of the environment and the needs of the Indians in their daily life. Above all, their job is to bring rain to the dry Hopi lands. There are other dances for abundant harvests, good health, peace and special occasions.

Over the centuries -- Oraibi, one of the Hopi villages, may be the oldest continuously populated community in North America, dating back some 900 years -- the Kachina cult has preserved and continued the old rituals. Youngsters are initiated into the society at about 10 years of age and trained for the roles of the large cast of Kachina characters -- estimated between 250 and 350.

The dolls in the Smithsonian exhibit are eye-catching, showing the magnificent masks and multi-colored costumes of the Kachina dancers. Architect Owings, who collects Kachina dolls on visits to Hopi ceremonial dances, has contributed many of the marvelous doll figures for the Smithsonian exhibit. Hopis consider Kachina masks and other artifacts to be too sacred for public exhibit away from the villages.

Included in the Kachina pantheon is an assemblage of clowns, who come forth during dance intermissions to mock villages and miscreants in much the manner of Shakespeare's fools. Many wear horizontially-striped costumes and sport an elongated pair of plumed ears sprouting from the tops of their heads.

Pat Burke, the project coordinator for the California Academy of Sciences, which organized the traveling exhibit, remembers her experience with a Kachina clown at a ceremonial dance-ritual last year in a Hopi village. It is an example, however frivolous, of the manner in which the Hopis have adapted to changing ways while insuring the continuity of their culture.

"While watching the Kachina dancers," Burke recalls, "I was captured by a Koshare clown. That's the figure there in the exhibit -- eating a watermelon. But instead of the long pointed ears, he had Mickey Mouse ears."