You might call it an elitist fireworks display. It was held on the Mall, the symbolic center of this democratic nation. But nobody was told about it except 1,500 people invited to a corporately sponsored ball celebrating George Washington's 250th birthday held in a Smithsonian museum.

The fireworks display took place near midnight on Monday behind the National Museum of American History, 14th Street and Constitution Avenue NW, as the ball sponsored by the Connecticut-based United Technologies Corp. was breaking up.

Among the guests were Secretary of State Alexander M. Haig Jr., former president and chief operating officer of United Technologies, and Secretary of Defense Caspar M. Weinberger.

The unexpected pyrotechnics led dozens of alarmed or puzzled citizens to telephone police and this newspaper's switchboard to ask what was happening. One resident of Alexandria said he awakened hearing what sounded like cannon firing.

Despite its highly visible central location, a spokeswoman for the museum said she was instructed by her bosses that no advance public notice should be given of the display because they didn't want a crowd to assemble for safety reasons. However, Park Police said about 200 people apparently got wind of the plans and showed up.

A spokeswoman for National Capital Parks, which has jurisdiction over the Mall, said her agency had not announced the fireworks but would reconsider its policy that sponsoring agencies are solely responsible for announcing events in that area.