Two beautiful museums -- beautiful but flawed -- open here at noon tomorrow just south of the Smithsonian Institution's fanciful brick Castle at the midpoint of the Mall. Congratulations to their founders, their scholars and their staffs. Their nine inaugural exhibits have been thoughtfully conceived and handsomely installed. The catalogues, the labels, the colors of the walls, and especially the objects from Africa and Asia selected for display, everywhere suggest high competence and care.

Among these these carvings, masks and guardians, these jades and antique bronzes, are objects of a power that will shake the ways in which ethnocentric westerners apprehend the sacred and the cyclic flow of time. The National Museum of African Art and the Arthur M. Sackler Gallery will be admired from the start, maybe even loved -- in spite of their one great defect. Both of these museums arrive partly maimed.

I know about the site's constraints, the continuous delights of the new Enid A. Haupt Garden, and the need to build the Sackler adjacent to the Freer Gallery of Art -- but may this be the last time national museums are constructed underground.

Ninety-six percent of the $73.2 million structure has been buried below grade. Despite the tricks of the designer, architect Jean-Paul Carlhian, his opulent materials and the skillful installations, there is no way to forget the compressing weight of earth and concrete overhead. Museums, like cathedrals, hymn the aspirational. Their spaces ought to soar. These instead feel crushed.

That architectural misjudgment is to some degree suggested by one of the borrowed masterworks in "African Art in the Cycle of Life," perhaps the most imposing of the opening exhibits. It is a wood mask from the Ijo peoples of Nigeria. Otobo is its name. Half-hippopotamus, half-human, it is as dark and geometric as a work by Louise Nevelson. Otobo was not worn on the face, but horizontally atop the head, gazing at the sky. There is a message in its glance.

The Sackler's Chinese jades and bronzes were buried with the dead, but their forms suggest a brightness. Works of sacred sculpture, brought alive by shifting shadows, yearn for living daylight. Before objects of such presence the soul should somehow lift. Here, though only subtly, one feels constantly oppressed.

Though the architecture disappoints, both new institutions much enrich the Mall. The two museums differ greatly, yet are exceptionally well matched.

Descending to their galleries, the viewer must abandon many, but not all, of the densely layered memories and deeply held assumptions with which he looks at western art. Were these fine jade blades from China, smoothed 4,000 years ago, used for human sacrifice, or were they gifts for the dead? There is no way of knowing, yet how is one to view an object that might be as ghost-ridden as a scaffold or as nicely ostentatious as a ceremonial sword?

That sense of meaning stripped away is just as keenly felt in the African museum. What function did that object serve? Did it curse, protect, or cure? The African Museum, more so than the Sackler, seems a purist institution. Almost all its objects have been placed in gleaming cases and somehow stripped of context. Was that carving danced or carried, was it placed in public view or only seen in secrecy in some initiation site? What music swirled around it once? What powers did that god command, with what voice did he call?

Yet the finest of these objects are never wholly mute. That's what makes them so amazing. Their sacredness and beauty slices through our ignorance. We may not hear them rightly, but nonetheless they speak.

Of the two museums, the African in some ways is more varied, more accessible. The Sackler, though it does contain Buddhist temple sculptures from India and Cambodia, some painted Persian miniatures, a superb bronze stag cast in Central Asia, and much old silver from Iran, is ruled by Chinese art. Though the West has been in awe of the artistry of China since the days of Marco Polo, though the Freer has been exhibiting Chinese jades and bronzes since 1923 -- and though carvings brought from Africa were not long ago regarded as ethnographic curiosities -- our eyes have somehow opened. The Sackler's many Chinese bronzes, though undeniably impressive, remain far more mysterious, more alien to modern eyes, than the monuments from Africa on display next door.

Among the masterpieces borrowed for Roy Sieber and Roslyn Adele Walker's "African Art in the Cycle of Life" is a bronze head from Nigeria from the British Museum, a 16th-century casting seized in 1897 from the Kingdom of Benin. One glance at her features, so great is her repose, authority and beauty, is enough to tell the viewer he is looking at a queen. The Sackler's antique bronzes, and even its 20th-century paintings, rarely speak so clearly. If the average western viewer -- inured to shifting fashion and dependent on his watch -- is baffled by such objects, it is because of their characteristically Chinese attitude toward time.

Objects made in Africa share a kind of nowness. Some portion of their spirit seems anchored to a kind of timeless present.

"I was once shown a broken terra-cotta figure of a queen mother among the Kwahu of Ghana," writes Sieber in his catalogue. "The chief who showed it to me noted that it was newly broken and that it would now have to be replaced. The broken one was said to be the funerary terra-cotta made for the first queen mother of the village some two-and-one-half centuries earlier. However, it was, in style, no more than about 30 years old. It was a replacement, removed an unknown number of times from the original, and yet was spoken of as if it were the original." Like many of the objects in the African museum, it seems removed from time.

Very few of them are old. True, that Nok head from Nigeria was made perhaps 3,000 years ago, and the Dogon rider near it might date from the 10th century, but they were not made to last. There are two life-size tomb figures here, from the Sakalava of Madagascar, that were left out in the woods to rot. Washington has never seen anything quite like them. They've been smoothed by years of rain. African art, one gathers, was used, and then used up, then uncomplainingly replaced.

Chinese art, in contrast, seems to fight for freedom from the ever-changing present. It is perhaps no wonder that the densest exhibition on view at the Sackler is called "In Praise of Ancestors: Ritual Objects from China." Almost all the Chinese objects displayed in that museum, even those from our own age, reach deep into the past.

Among the newest objects in "Pavilions and Immortal Mountains: Chinese Decorative Art and Painting" is "Bird, Rock and Chrysanthemums," a hanging scroll by Qi Baishi (1863-1957). Though painted in the '20s, its style, quite intentionally, pays homage to the past. Its brushwork strives to imitate that of Zhu Da (1626-1705). Even Qi Baishi's signature has an antiquarian spirit. It is written in the style of another long dead painter, Jin Nong (1687-1764).

That sense of continuity is sensed from the beginning in the Sackler's Chinese art. Perhaps the oldest of the bronzes here, a Lei from the Shang dynasty, a ritual wine container from the 15th century B.C., takes its simple form from even older pots of clay. The oldest jades suggest a similar archaism. They were not made for use, yet look like Stone Age tools.

"In contrast to developments elsewhere throughout the ancient world," writes director Thomas Lawton, "Chinese artists did not abandon their Neolithic traditions when the casting of bronze ritual vessels developed during the historical Shang (ca. 1700-ca. 1050 B.C.) and Zhou (ca. 1050-221 B.C.) periods. . .Traditions were perpetuated, and functional implements like stone harvesting knives and sturdy stone chisels were fashioned of precious jade."

No one knows the use, much less the iconography, of the jade discs at the Sackler, some of which were made more than 4,000 years ago. Yet similar discs of jade were being imitated carefully by skillful Chinese artists in the 18th century.

That antiquarian yearning is as old as Chinese art. Among the bronzes at the Sackler is a Zhou dynasty Jing Gui, a ritual food container from the 10th century B.C. That old pot held an honored place in the Emperor's collection -- until British and French troops sacked the Yuanmingyuan, the "Old Summer Palace," in 1860. One cannot escape feeling that this ancient bronze was made to be embedded in the stream of time. According to its 90-character inscription, the Jing Gui was intended to be used for the next 10,000 years.

The Sackler, at its opening, makes no attempt to survey all of Asian art. There is almost nothing from Korea or, for that matter, Japan, in its four inaugural exhibitions. Of the 1,000 objects on display -- all owned by the museum -- some 700 are Chinese. The new museum's holdings might well seem out of balance, were it not apparent that the Sackler was conceived as a sort of adjunct and extension to the Freer.

You would have to be a specialist in the arts of China, and a dedicated scholar, before you could unwrap all the layers of allusion wrapped around the Chinese things in Arthur Sackler's fine collection. The museum's Lucia Pierce, who curated "Monsters, Myths and Minerals," the teaching show, has done his best to lend the viewer a kind of helping hand.

His instructive installation calls particular attention to the various birds and animals that recur through the millennia of the Middle Kingdom's art.

Some suggest the compass and the calendar: The east, we learn, is guarded by the dragon of the spring, the south by summer's phoenix, the west by the white tiger of autumn, and the north by the hibernating tortoise of winter. But these symbolic creatures suggest much more as well. Take the dragon, for example. A label on the wall, quoting from Okakura Kakozo's "Book of Tea," defines that wondrous being as the "great mystery itself."

"He unfolds himself into the storm clouds, he washes his mane in the darkness of the seething whirlpools. His claws are the fork of the lightning, his voice is heard in the hurricane. . .The dragon reveals himself only to vanish." His image can be found in a pendant that was carved ca. 1200 B.C., in another splendid pendant made 800 years later, in a 14th-century finial, a 16th-century lacquer dish, and throughout Chinese art.

Other beasts appear as well, each with its complex message. The crane suggests longevity; the hen and the cock phoenix, the relationship between bride and groom; the bear, great strength; the ram, good luck. The decorative art exhibit includes extraordinary furniture (there is little at the Freer), and bowls and inkstand boxes. China, unlike Africa, was united through the ages by a common written language. The Chinese exhibitions make that truth apparent. The colors of the jades, those browns and greens and beiges, the patinas of the bronzes, the brushwork of the scrolls and the details of the furniture, may not need translation. But almost all this Chinese art requires a sort of literacy. To see you have to read.

The Sackler's Near Eastern material is in many ways less veiled, and somehow easier to reach. If you have ever seen the swagger of a large-horned bull, you will recognize the tread of that Anatolian casting from the third millennium B.C. That bull may be a symbol, but it is not a symbol only. The Rhytons here, the animal-headed drinking horns with their lions and their lynxes (they are probably from Iran), are tied to life as closely as they are to art.

One of Arthur Sackler's most intriguing buys was a horde of ancient silver. It includes bowls, blades and bracelets, and other silver objects, 56 in all. Their origins are obscure. They may be Iranian, they may date from the second millennium B.C. (though that date is far from certain). Among those antique treasures is a set of unfamiliar animals of graduated size. The smallest weighs 23 grams; the heaviest 2,782 grams. Each of these strange beasts has the tail of a cheetah and the flat nose of a pig.

Despite some cases made for children, and suggestive installations, some with tile roofs and moon gates (they were designed with much finesse by the museum's Patrick Sears), the Sackler, one suspects, will have a bit of difficulty in luring a broad public. Future touring shows may well bring in crowds, but the new museum, like its older neighbor (the two distinct museums will eventually be linked) is likely to retain the dignity and quiet of a research institution.

When I think about the Sackler, the many jades and bronzes there begin to form in memory a sort of smooth continuum, a composite of China's art. That is not at all what happens in the African museum. The objects there (most of which are borrowed) share nothing half so much as their individuality. The strongest things on view seem to reach out of the cases. They grab you by the throat.

The history of western sculpture tends to be remembered as a sort of chain of masterworks: The Venus of Willendorf, the head of Nefertiti, the Discobolus of Myron, the Apollo Belvedere, the Winged Victory of Samothrace, the David and the rest form themselves in memory into a kind of dotted line. Fifty years ago, perhaps even 20, few scholars could have drawn up any sort of list of the finest things from Africa, the standard-setting objects by which such art is judged. That that situation is now changing is clear in this museum.

Of the 84 sub-Saharan objects included in "African Art in the Cycle of Life," at least a dozen of the strongest are, by now, familiar. Some were seen in "African Sculpture," the grand, pioneering survey organized by William Fagg, which opened at the National Gallery of Art in 1970. Others have been in various exhibitions at the African Museum (before it was reborn in its new home on the Mall), and in William Rubin's "Primitivism" show, which opened in Manhattan at the Museum of Modern Art in 1984.

The curators who picked the "Cycle" show have done their best to borrow nothing but the finest. Director Sylvia H. Williams has been comparably demanding in the objects she has sought out for the African museum's (still relatively small) permanent collection. The museum, as it opens, is offering the public what -- today by consensus -- is some of Africa's best art.

But "best" is an elastic word. We still have much to learn about most of these grand objects. With a few exceptions -- a Yoruba divination board that found its way to Europe before 1659, or an equestrian Dogon figure (dated by radiocarbon analysis to 945-1235 A.D.) -- their ages are not known. Nor are their sculptors' names (though two works on display were made by Olowe of Ise, a great Yoruba carver who died in 1938. One of these, a palace door, carved in high relief, was traded to the British Museum in 1924 by the Yoruba king in exchange for a specially designed made-in-England throne). Yet another factor might shake a westerner's belief in the grandeur of these objects. They are not all unique.

That queen's head from Benin, lent by the British Museum, resembles very closely a sculpture that was seen in the 1970 National Gallery exhibition. (The two castings look so much alike it is considered more than likely they were made by the same hand.) The Kuba statue of Shyaam a-Mbul a-Ngwoong now at the museum is in many ways a twin of the Kuba statue of King Bom Bosh seen here 17 years ago, though the one that's now on view (it comes from the British Museum) consults a divination board, while the Brooklyn Museum's King Bom Bosh instead plays a drum.

While China has been unified for many thousands of years, Africa is still splintered into nations, kingdoms, tribes -- into subgroups beyond counting -- each with its own heroes, traditions and beliefs. The works at the museum display, at least at first glimpse, a variety that's staggering. Some are scary, some are poignant, some are ivory, some bronze. Yet look at them awhile, and their differences begin to fade. For there is much they share.

That subtle commonality is thoughtfully explored by the Sieber-Walker "Cycles" show. While chosen for their quality, the objects have been grouped to make apparent certain constant themes common throughout Africa -- such as parenting and bonding and other forms of continuity, or initiation rituals and other rites of passage, or status and display, or Africa's response to European culture, or remembrance of the dead.

These objects were not made just for self-expression, or to please grandees, but for functions more far-reaching. Almost all of them were used.

Some were used for governance. A Yombe Nkisi Nkondi from Chicago's Field Museum is a bearded male statue whose upper arms and torso have been studded front and rear with countless bits of metal, iron blades, machine parts, nails, rusted screws. Each separate bit of metal -- like the falling, in the West, of a judge's gavel -- signifies agreement, say, a peace treaty concluded, or a land title transferred, or a dispute resolved.

Some were used for regal displays of authority. Among the most intriguing objects is a chief's chair from Angola carved with competing suitors, revered ancestral heroes and a group of hanging bats.

Some were used in divination, some in healing, some in war. But many things were produced, or so it seems, primarily for pleasure. "Objects of Use," a terrific little show cocurated by Andrea Nicolls and director Williams, includes such modest artifacts as hairpins made of ivory, stools, snuff bottles and baskets. These mild works convey no overpowering message. Yet that little wooden pipe, its bowl a naked woman, and the snuff spoon and bottle next to it, rank among the loveliest objects on display.

Five separate exhibits (all designed by Richard Franklin, whose unobtrusive installations, despite their great variety, never yell out for attention) open the museum. Two of these exhibits -- "Objects of Use" and "Cycles of Life" -- are exceptionally fine loan shows. A selection of highlights from the permanent collection, liberally salted with some extraordinary loans (which one hopes are promised gifts), is also on display. So is a collection of bronze plaques from Benin -- most of which were purchased by the late Joseph H. Hirshhorn for his own museum. Its 16th-century castings look both old and new. At the entrance to that show is a recent photograph of the kingdom's current ruler. The coral net he wears on his ceremonial gowns is just like that which binds the bronze queen mother's gathered hair.

The fifth exhibition is devoted to strip weavings from West Africa. Their designs are in some ways as rhythmic and complex as those of Persian carpets, and in other ways as open as stripe paintings by Gene Davis. Those generous, uncluttered, boldly designed fabrics bring to the museum the one thing that its artists, its scholars and its craftsmen, were hard pressed to provide -- a sense of light and air.