THE Louvre museum celebrates its 200th birthday on Nov. 18. On that same day, another perhaps more memorable event will take place: France's President Francois Mitterrand is expected to inaugurate the Richelieu wing of the Grand Louvre complex.
The opening of the wing, which forms the northern side of the Louvre palace's U-shape, marks the culmination of architect I.M. Pei's monumental 10-year, $1.2 billion project to revamp one of the world's richest museums. From 1871 until 1989 the Richelieu wing housed the Ministry of Finance which, after much resistance, was finally relocated, giving the Louvre the long-awaited chance to double its exhibition space.
Restoration began three years ago. Built in the mid-1850s under Napoleon III, the Richelieu wing had become a maze of offices and had to be almost gutted and rebuilt, with the exception of several period rooms - the salons Morny - that have been carefully preserved to maintain their original 19th-century opulence.
Mr. Pei chose two French architects, Michel Macary and Jean-Michel Wilmotte, to collaborate with him on the Richelieu project. Mr. Macary is responsible for much of the ground floor, including the two large courtyards, newly baptized Puget and Marly after a 17th-century sculptor and an 18th-century sculpture.
The Ministry of Finance had used the open courtyards as parking lots; Pei and Macary decided to cover them so that they could be used as exhibition space. The glass roof is supported by aluminum bars that filter the sunlight; a technique that Pei has used on other projects. French sculpture ranging from the Middle Ages to the 19th century will be exhibited in the Puget and Marly courtyards.
A third and smaller courtyard was also covered and named Khorsabad after the ancient Assyrian city and 8th-century palace. Elements from the palace are stunningly represented, including a section reproduced from photographs of the original layout found during archaeological excavations. A copy of one of the Khorsabad winged bulls in bas-relief, which is located in Chicago, was made to join its brother bulls in the Louvre collection.
THE remaining space on the ground floor will be used to exhibit Near-Eastern antiques. The smaller items are in glass cases designed by Mr. Wilmotte, who used an innovative system of fiber optics in tiny spotlights to diffuse the light, rather than the usual fluorescent lighting.
One level below, the Louvre can now show off its rich Islamic collection in its entirety - something the museum has never had the space to do before. Objects from Spain to India are exhibited in chronological order (8th century to 19th century) in 13 rooms, some with vaulted ceilings.
Pei has retained three 19th-century stairways from the original structure, and designed a streamlined escalator that leads to the first floor and the department of objects d'art, designed by Wilmotte.
The greatest challenge for Wilmotte was the problem of scale. Small objects and very large pieces, such as tapestries, had to cohabit in vast areas. A visit to the floor, which contains more than 3,000 objects, might begin with the Byzantine section, then on to articles from the Middle Ages and through two gallery spaces conceived to house the 16th-century tapestry series ``Maximillian's Hunters'' and ``The Story of Scipio.''
The Morny salons are included in the objects d'art circuit. Named after the Duke of Morny, who served briefly as minister of the interior under Napoleon III, the gilded rooms are ostentatious examples of mid-19th-century decor which, according to Yann Weymouth, one of Pei's architects, even inspired an American architect in the latter part of the century to import what became the Newport (R.I.) style to the United States.
The Richelieu wing's top floor is an extension of the Louvre's picture galleries. The Northern school paintings, which could previously only be seen on two days during the week, are now comfortably settled in their new area.
Much thought went into the lighting method for the painting galleries. Pei and his team came up with a system of ``zenithal'' lighting, which uses as little artificial light as possible and, when necessary, ensures that the artificial light is evenly distributed. During the summer the museum plans to use only natural light - this aspect was so important that a mockup of one of the galleries was set up in the Tuilleries gardens for more than two years to test the natural light.
To allow more natural light to enter the rooms, the roof was opened and skylights were installed. False ceilings in plaster were put in containing fluorescent lights that reflect off screens over the skylights, thus diffusing the light. (Unfortunately the curator of paintings decided to have the walls in many of the rooms painted mauve and dark green, darkening the soft natural light.)
Running on a north-south axis with Pei's famous pyramid is the Rubens gallery. In it, 27 large-scale paintings (only 24 were exhibited previously) executed by Rubens in the 1620s represent the glorious moments in Maria de Medici's life. The paintings are set into niches in the walls and are fittingly described by Weymouth, who was in charge of design for the top floor, as a 17th-century comic strip.
Besides its precious Rembrandts, Vermeers, Van Dykes, and Breughels, the top floor of the Richelieu building affords a stunning panorama of Paris rooftops and the Sacre Coeur cathedral from the rooms facing north and a fine view of Pei's glass pyramid entrance to the Louvre, facing south.
One might expect a certain disunity in the new wing, due to the combined work of several architects, but the design is coherent in its simple lines while the use of wood and stone give a sense of peacefulness to the large exhibition spaces.
OCTOBER saw the opening of a sparkling new inverted pyramid to allow light to enter the Louvre's underground complex, new parking facilities, a shopping mall, and archaeological excavations. Work on the entire Grand Louvre complex isn't estimated to end until 1997, but the completion of the Richelieu wing is the final phase in the massive overhaul of the museum proper.
In 10 years, Pei has made it possible for the more than three million annual visitors to the Louvre who used to flounder about in its labyrinthine halls, to find their way around; the new wing should make it even easier.
* The Musee du Grand Louvre is open from 9 a.m. to 6 p.m. daily, closed Tuesday. On Monday and Wednesday evenings, it is open until 9:45 p.m.