HOW FLEETING IS FAME: At the National Portrait Gallery through July. Daily, 10 to 5:30.

Who can forget that hilarious comedy team, Florence and Florence, stars of Yankee girl-Irish boy farces in the 1880s, applauded for three and a half decades on the American stage?

Or that national treasure, renowned naval officer and inventor Charles Dwight Sigsbee, whose namesake is The Sigsbee Deep, in the center of the Gulf of Mexico?

Not to overlook the legendary daguerreo-type artists Charles and Henry Meade, journalist Thurlow Weed and Sen. Hiram Rhoades Revels (Republican of Mississippi, 1870-1).

Names don't ring a bell, you say, but maybe if you saw the faces? Forget it. The National Portrait Gallery makes the point, "How Fleeting Is Fame," by dusting off lithographs of these and other once-famous faces. Included are artists, politicians, reformers, soldiers, scientists and entertainers: celebs in their day, gone now but -- forgotten.

Since it was easier and cheaper to draw on stone than to engrave a copperplate in the 19th century, lithographers were the primary picture dealers of their day. Portraits were their stock items, cranked out quickly for commercial reasons and sold before the next crop of the briefly famous seized the public imagination.