If some of the security people had their way during World War II, President Franklin D. Roosevelt would have been living in the Black House. And, to make the presidential residence less identifiable to enemy bombers, the courses of the Potomac and Anacostia rivers would have been changed.

We're not kidding. But, presumably, neither are the Secret Service people who now are thinking of disrupting the life of the nation's capital by closing off Pennsylvania Avenue between 15th and 17th streets to achieve the worthy goal of protecting the president.

While security people during World War II were mindful of the dangers of terrorist bombs, their main worry was the prospect of German bombers reaching the airspace above Washington.

Washington Post library researcher Mary Lou White called attention to a book that dealt with the subject. "Reilly at the White House," the reminiscences of Michael F. Reilly, the Secret Service agent in charge of FDR's security during the war, recounted these deliberations by some high-powered security experts who convened shortly after Pearl Harbor:

"Among other things it was suggested that the White House should be painted black, the national capital should be moved inland away from the East Coast, and the course of the Potomac and Anacostia rivers should be changed.

"The latter was not quite as silly as it sounds, because no camouflage of the White House is practical while the confluence of these rivers remains a mile actually about three miles from the mansion. A pilot would find it quite simple to hit the White House by flying up either river and getting his 'fix' at the confluence."

Reilly, who died in 1973, also said it was he who -- to avert possible terrorist bombings -- asked the D.C. Board of Commissioners to close East and West Executive avenues to traffic.

"The east and west wings of the White House extend to the sidewalks bordering these streets, and the president's office is not 15 feet an exaggeration off West Executive Avenue," Reilly wrote.

West Executive never was reopened, but East Executive was restored after the war to public use until, with the excuse of security, it was converted last year into a parking lot for White House employes.