Only rarely does an exhibition come along that presents Americans with a clear insight into the depth and range of their artistic heritage. More than enough exhibitions devoted to specific American artists or historical periods, or to in-depth studies of well-known or dimly remembered art movements, have been mounted. And several exhibitions exploring the art of particular centuries have seen the light of day.
But exhibitions devoted to the grand swing of American art as it moved from century to century or to large numbers of its all-time major works have been rare indeed.
A crucial factor has been one of quality. There simply aren't that many truly major American paintings, and neither have there been that many truly significant American artists. Those we've had have frequently been erratic. Some of our best painters produced only a handful of excellent works among many of doubtful merit, while a few of our minor artists miraculously managed to turn out one or two paintings that were truly superb.
In addition, assembling such an exhibition poses serious problems in logistics. The best American paintings are scattered throughout the United States in numerous public and private collections.
The Museum of Fine Arts, Boston, however, has surmounted all obstacles to present ''A New World: Masterpieces of American Painting, 1760-1910'' on view here. It was organized by Theodore E. Stebbins Jr., John Moors Cabot curator of American paintings at the museum, in response to a request from the Musee du Louvre to mount an exhibition of superior American paintings. Not only has he done so, he has also presented the American public with its first full view - in considerably over a decade - of American art at its best from the years preceding the American Revolution to those preceding World War I.
The exhibition itself is superb. Its 110 paintings by 49 artists include only what its organizer considers the best examples by those represented, with a primary focus on the work of the 10 painters currently considered outstanding for their time. John Singleton Copley, Thomas Cole, Frederic Church, Martin Johnson Heade, Fitz Hugh Lane, George Caleb Bingham, William Sidney Mount, William Harnett, Winslow Homer, and Thomas Eakins are all well represented. (Interestingly enough, 35 years ago, Albert Pinkham Ryder would have been near the head of that list, and Church, Lane, and Heade would not have been on it.)
Also well represented are those perennial favorites Mary Cassatt, James McNeill Whistler, and Albert Bierstadt, who score popular successes with ''The Bath,'' ''Arrangement in Grey and Black: Portrait of the Artist's Mother'' (also known as ''Whistler's Mother''), and ''The Sierra Nevada in California,'' respectively.
I have never seen Eakins looking so good. The museum's Graham Gund Gallery is spacious and light and does its share to help reveal subtleties in Eakins's color and draftsmanship that too often remain hidden in shadows. ''The Gross Clinic'' (what a painting that is!) seems more physically painterly here than I've ever seen it, and ''The Thinker'' comes across as more psychologically effective.
Homer also stands out. Every one of his canvases, even his earlier and more illustrational ''Snap the Whip,'' projects his special combination of authenticity, painterly pleasure, and rough-edged romanticism. I was particularly pleased to see ''A Summer Night'' on loan from the Louvre and once again in the company of ''Sunlight on the Coast'' and ''West Point, Prout's Neck.'' If they don't prove to everyone's satisfaction that Homer was an exceptional painter, I'll be very much surprised.
So many paintings call attention to themselves: Copley's ''Boy With a Squirrel,'' Benjamin West's ''Death on the Pale Horse'' (from a distance it resembles a Rubens oil sketch), all of Church's landscapes, Frank Duveneck's ''The Turkish Page,'' Harnett's ''Trophy of the Hunt,'' Frederic Remington's ''Evening on a Cana
dian Lake'' (despite the artist's unfortunate choice of color for the water), and John Singer Sargent's ''Venetian Interior.''
In all, an excellent and a very popular show - judging from the reactions of the many visitors in attendance the day I saw it. It would be difficult to challenge more than two or three of the works included (I found Edward Goodes's ''Fishbowl Fantasy,'' for instance, the sort of painting only an art historian could like), and the overall ensemble effect was truly stunning. It is the sort of exhibition we should send to other countries besides France. It would show the world that earlier American art did have many excellent and outstanding qualities.
What it will not do, I'm afraid, is convince anyone that the United States has produced a truly great painter. Almost great, yes, we have had two or three that fit that category. But actually great? No, I'm afraid not.
We should keep that in mind as we pay tribute to the art our major painters have produced. I do not intend to demean the likes of Eakins, Homer, Cassatt, Whistler, Copley, or the rest by saying that, for all its impact and importance, this exhibition cannot match what the current Manet exhibition at the Metropolitan Museum offers in the way of artistic greatness. And even with that, we must take into account that Manet was only one of 10 or so great painters France produced during the 19th century.
''A New World'' will remain on view at the Museum of Fine Arts, Boston, through Nov. 13. It then travels to the Corcoran Gallery of Art in Washington, D.C. (Dec. 7-Feb. 12, 1984); and to the Grand Palais in Paris (under the auspices of the Louvre) March 17-June 11, 1984.