"We must have very solid things, made to last a hundred years," said Emperor Napoleon Bonaparte, defending his imperial-sized household budget in 1807, three years after he crowned himself in Notre Dame.

Napoleon's "very solid things" certainly heeded the royal command, lasting far longer than the century he specified and speading far beyond the country he ruled. Art often out-lasts empires.

"The Arts Under Napoleon" - the first exhibiton of decorative arts of the Napoleonic era to be held in New York - is open through July 30 at the Metropolitan Museum of Art. More than 250 objects made from 1799 to 1815 represent the culmination of the classical revival and the last great French decorative style before art moderne .

The style was equally popular abroad. Many foreign cabinetmakers bought French brass ornaments to [WORD ILLEGIBLE] their own works, as a Russian furniture setting in the show points up. The White House has several pieces of French Empire furniture, the remains of a much larger suite chosen by President James Monroe in 1817, including seven gilded chairs by Pierre-Antoine Bellange. (They arrived with the notation that the mahogany Monroe ordered was "not generally admitted in the furniture of a saloon, even at private gentlemen's houses.") French Empire has continued in popularity. For years, almost all embassies of whatever country in whatever climate were furnished in French Empire style.

The magnificent tresures of Tutankhamun, shown at Washington's National Gallery in November. 1976, will end their country-wide tour with a showing late this year at the Metropolitan. King Tut's royal progress has sparked an Egyptian revival in the United States in everything from sheets to eyeshadow. So it seems appropriate that the Metropolitan show the Empire style, which included an earlier Egyptian design revival another of the phoenix-like-risings of the Kings Who Live Forever (if only in patterns by the yard).

(Napoleon, of course, knew nothing of Tut, since his tomb was only discovered in 1922, but the French conquerer's Egyptian campaigns in 1798 expanded his great interest in antiquities, which had begun with Greek and Roman art and political philosophy.)

The arts under Napoleon, of course, were not eraly so splendid as the arts under Tutankhamun, though there are points of similarity. Napoleon's regin, from 1804 to 1815, was hardly long enough to get delivery on all the magnificient objects d'art he ordered. King Tut (1347 to 1335 B.C.) had to be buried in somebody else's tomb, probably with someone else's treasures. The glitter of gold (solid in Tut's collection, plated in Napoleon's) is the one after image that lingers in both shows. The two kings fancied strong, vivid, imperial colors to stand up to gold.

The king shared a taste for grandeur - simplicity of design, elegance of material, solidarity of craftsmanship. Napoleon scribbled across a sketch for a candelabrum "Simplify. This is for the Emperor."

Of course, a craftsman's idea of simplicity in Napoleon's day and simplicity today are not altogether the same.

A mahogany cabinet for medals in the Egyptian taste is the most beautiful object in the show. The cabinet combines in one piece the work of the best of the Empire designers and craftsmen. It was made for Dominique Vivant Denon, who had sketched the scenes of Napoleon's Egyptian triumph. Denon designed the cabinet with the help of architect Charles Percier and had it made by the cabinetmaker Jacob Desmalter and the silversmith Martin-Guillaume Beinnais.

The cabinet is inlaid with silver and fashioned after the shape and the ornamention of the Ghoos pylon in Upper Egypt. Its beautifully stylized design forecasts both the art nouveau and the art moderne style to follow. The cabinet manages to be both simple and elegant, a timeless triumph.

At the other extreme of the Empire is the Pierre-Philippe Thomire inkstand with its center gilt bronze statuette of a king standing on a pedestal mounted with symbol of virtue. Eight roundels on the glass base bear the names of Spanish Renaissance writers and philsophers and are set with four ivory heads of Muses painted to look like cameos. At the corners, four gilt bronze inkwells actually hold ink. The malachite base has a frieze of gilt bronze ornamented with classical deities, and at the corners, gilt bronze mounts of symbols of war, agriculture, medicine and the arts.

In the splendid catalog by James David Draper, the Metropolitan's associated curator of European sculpture and decorative arts, there are many good stories, including one (retold from Madame Junot, a gossip of the period) illustrating how kings and kin are different from you and me.

Napoleon and Josephine were great patrons of the silversmith and cabinetmaker Biennais. Even so, they were not altogether pleased and indeed somewhat horrified when ". . . a large bill was presented in 1800 for a necessaire lavishly outfitted with razors, shaving brushes, combs and other instruments exclusive to shaving. The purchaser of this luxury was Napoleon's brother Jerome, a sybaric - and beardless - 15 years old."

Heaven knows, Napoleon tried to curb his family's appetite for luxuries, Draper said, showing visitors through the exhibit. To protect the French silk workers, Napoleon decreed that all members of the court could only wear finery made in France. But Josephine and his sisters would not give up their cashmere shawls.

Napoleon, however, really didn't except his women to keep a sour face and wear a plan perricoat. (Though he did once order, somewhat futilely, that the border of a lady's train could be no longer than four inches. Draper noted, "The graceful lines must have altered considerably when ladies had to bundle their trains and run after the Emperor who walked very fast in processions.") According to Draper, Madame de Remusat, another gossip, wrote that in 1806, while Napoleon fought in Poland, Josephine and her court were sent back to Paris with orders from Talleyrand: "Ladies, this is no laughing matter; the Emperor insists you amuse yourself."

One way was with a clock made of bronze gilt, manufactured by Antoine-Andre Ravrio (the man who later offered a reward for the inventor who could protect clockmakers from mercurry poisoning suffered while gilding). The clock, lent by the Cooper-Hewitt Museum here, was mounted on a semicircle with lyres and winged beasties surmounted with cupids and a medallion of a goddesses. On a stage below, a magnificent palace room is detailed with more goddesses on panels, draperies and a splendid harpsicord with griffins for legs and a goddess for a pianist.

The clock was not unique. Ravrio was a man of business. A similar clock, but this one with a musical movement, is in the collection of Prince Napeleon, the reigning descendant of the family. Still another edition of the clock will be auctioned off at Sotheby-Parke Bernet's on May 6 and is expected to bring $5,000-$6,000.

The show is full of other wonderful things - both from the Metropolitan's own treasure chests as well as important loans, principally from the great New York collection of C. Ruxton Love Jr. It begins with winged Victories, candelabra of gilt bronze by Thomire. It ends with the great Demidoff Vase, more than eight feet high, of malachite (joined pieces) ornamented with gilt bronze figures of Fame.

In between are gold coins and bronze medallions; a fanciful traveling silver set for six people; swords of cut steel, coral and mother of pearl; firearms, richly ornamented with silver in velvet lined cases; lace veils; gold embroidered album covers; magnificent velvet dresses with long trains and men's contumes in purple, gold and silver; and drawings by Percier and Pierre Francois Fontaine, the architects of the Empire interior style.

Napoleon, according to Draper, justified much of his extravagance by explaining that he had to provide work for his country's great craftsmen, who had fallen upon lean times during the revolution. It is true - Egyptian or French or American - if there are no rich patrons there will be no solvent craftsman.