YANG KI "vases of the sea" - was the name, pretty but perhaps derisive, given by the Chinese to porcelain wares made for overseas markets.

Today, prices of Chinese Export porcelain seem to be about level with gold. Then, Chinese porcelain makers considered the ware to be good enough for the foreign devils, but not up to the standards of Chinese nobility.

Much of the porcelain exported was cheap everyday ware, and sold as such. The ship didn't sail to China for porcelain. The China commerce was based on tea first, silk second.Porcelain was something to use for ballast.

Yet Chinese Export porcelain intrigued people for several centuries. You can see why at "Yang Ki," a show of porcelain wares with connections to naval hero Stephan Decatur and other federal families. The exhibit will be at Decatur House on Jackson Place, Lafayette Square, for the rest of the year.

In the informative catalogue, Linda Cairns-Malatt makes a good point often overlooked:

"Unlike the high quality domestic porcelains manufactured for the Imperial Court, chinaware made for export was composed of inferior clays that often produce pitting bubbles, and a rough orange peel texture.

Even so, the splendid Decatur exhibit easily shows why Americans are so fascinated by these admittedly second-class objects. The best of the decorations are genre scenes, showing us what concerns preoccupied the Chinese and the Americans of the day. The other day Cairns-Malatt and her co-curator, Vicki E. Sopher, walked through the show, pointing out treasures.

A punchbowl, for instance, pictures Canton harbor, on the quarter-mile of bank along the Pearl River. Here were the hongs, or business offices, that dealt with the "flower flag devils," as they were called. You can see the flags flying from the deep porches. The wares that show Chinese scenes are especially charming.

The more expensive porcelain was made for special orders. The practice probably started when the Europeans ordering their coats of arms reproduced on china. Some china sets were "personalized" to use today's ugly word, very cheaply and unpleasantly - the artist would paint in the monogram on stock patterns. But some of the commissioned pieces are very handsome and among the most interesting.

The real prize of the Decatur House show is punchbowl just acquaired for the house. On the bowl is a first-rate painting of Stephan Decatur Sr., father of the builder of Decatur House, and a splendid eagle. Remarkably, the original of the portrait, a Saint Memin engraving, and a pitcher, similarly decorated with the portrait, are displayed in the same case. The elderDecatur had been a privateer. Later, he joined the American revolutionaries and fought and won notable battles. A medallion on the bowl commemorates his capture of the Incroyable, a French privateer. His ship, the Delaware, is carefully drawn here. Cairns-Malatt thinks probably the Canton artists were again working from an engraving. One of the other medallions cages a "flying sparrow" eagle, flying from his mouth a banner enscribed "E Pluribus Unum."

Another Decatur heirloom was a set of export china ornamented with nautical ship-building symbols, encircled with a band of seaweed and scallops shells. Cairns-Malatt notes that the ship on this set is in correct perspective instead of the more usual flat style.

Not nearly as much fun, but much more famous is the is the porcelain plate in the next case, the set ordered by members of the Society of the Cincinnati, the organization of the Revolutionary patriots. The plate displayed was one of George Washington's own, with a winged figure of Fame flying above the crest.

Elizabeth Chew, wife of the chief justice of Pennsylvania, sent a plate - in the neoclassical style so popular in France at the time - to China to be copied onto a 346-piece set of china. Greek ewers, urns and chests form a frieze on a canary yellow background, suitable for the grand style of entertaining at their country seat, Cliveden, Germantown, Pa. (now a National Trust for Historic Preservation property, as is Decatur House). A remarkable bit of documentation, the letter to the agent from Chew, ordering the set, is also in the case. She paid $120 Spanish dollars for the set.

One whole case displays a variety of eagle-decorated china, usually copied from coins or letterheads. Cairns-Malatt divides them into categories: sparrow eagle, flying eagle, bottle ticket eagle, pigeon eagle and medallion eagle.

In the Decatur bedroom are other Chinese export objects, free of confining cases, all placed as they might have been during those brief days when Decatur slept there. On the wash stand is a fine bowl, nearly a rose nedallion soap dish. On the table is a chocolate pot and cup decorated with the rare cherubs (you won't believe them). A barber dish (or a bleeding bowl), a Bordalove na female urinal allegedly church-going and named after a long-winded preacher), and a chamber pot show that Chinese export porcelain was not limited to the drawing and banquet rooms.

The show also wisely has some less often noted Chinese export items: an ivory fan with an intricate cut design, a silver mug and pot, a glass snuff box, an ivory puzzle box, among other beauties to rival the porcelain. CAPTION: Picture 1, A covered pitcher with the profile of Stephan Decatur; Picture 2, detail from a Decatur punchbowl bearing a ship medallion on its side. By Wm. Edmund Barrett - Decatur House; Picture 3, Helmet pitcher (c. 1785-1970).; Picture 4, American landscape sugar bowl.