There is something not quite right about the survey of American prints now on view at the National Museum of American Art. It's called "The Print in the United States from the 18th Century to the Present" (the present, in this case, being 1977), and it bites off more than it can chew.

Wandering among these 90 scattered objects, I suddenly remembered a beloved high-school teacher who, believing fair is fair, let her social studies students give her an exam. Our first question was a good one: "Trace the growth of democracy from the Ice Age to the present. Be brief but explicit: 4 minutes."

This exhibit opens with a modern restrike of America's first mezzotint, Peter Pelham's lively 1728 portrait of Cotton Mather, the divine. A mere six prints later, the 18th century is over. Moving right along -- we still have 177 years to cover -- we speedily arrive at the 1930s and the WPA. Janet A. Flint, the museum's curator of prints and drawings, tells us in her catalogue that "the various Graphic Art Projects employed several hundred artists, both young and established, who produced more than 80,000 impressions of more than 4,000 original prints." No survey of American prints can afford to overlook those urban objects. Guess how many are on view. Three.

This show, depending on your point of view, is too big or too small. There is too much ground to cover. Think of all the print technologies that have to be acknowledged -- metal engraving, wood engraving, stipple engraving, lithographs in color and in black and white, woodcut, etching, linoleum print. The list goes on and on.

The requirements of subject are equally demanding. In the days before the photograph, the print reported news. (Samuel Blodget, for example, engraved in 1755 a detailed account of the battle fought that year "between 2,000 Englishmen with 250 Mohawks . . . and 2,500 Frenchmen and Indians . . . in which the English were victorious, captivating the French general with a number of his men, killing 700 and putting the rest to flight.) Portraiture, of course, must be surveyed, too, and many famous figures -- Washington and Hamilton, Madison and Jay, Boss Tweed and Marilyn Monroe -- appear in these prints.

The cityscapes displayed include optimistic images by such accomplished printmakers as John Marin, Edward Hopper, Martin Lewis and Louis Lozowick, a charming 1734 rendering of Savannah (there's the Crane and Belle, apparently a tavern; there's the tent of Mr. Oglethorpe), and a charming view of Washington circa 1834. That little urban survey ends with a colored lithograph of a neon sign made by Robert Cottingham, the photo realist, in 1974.

Many famous printmakers -- Currier & Ives, Whistler and Homer, Stuart Davis and Ben Shahn, Frank Stella, Andy Warhol, Roy Lichtenstein and Richard Estes -- of course are represented. There are many handsome objects here -- Julius Bien's "American Flamingo" after J.J. Audubon, a 1922 engraving of the Brooklyn Bridge engraved by John Taylor Arms, a 1973 still life by Jim Dine and "Corpse and Mirror II," a 1976 color lithograph by Jasper Johns -- but this show is still a blur. It closes Jan. 17.