There are only three dozen or so paintings in "Landscapes From the Age of Impressionism," now at the Norton Museum of Art in West Palm Beach, but it's a fine little show, a sort of encapsulated history of its subject. Just over half of the works, all from the collection of the Brooklyn Museum, are American, with the remainder French. There are some big names here — Renoir, Manet, Pissarro, and Courbet among the Frenchmen; Childe Hassam, William Glackens, and John Singer Sargent among the Americans — although the majority of the artists will be unfamiliar to the average viewer. No matter. They're almost all luminaries in this context. And there's a handful of to-the-point wall panels to provide context, tracing the movement from its mid-19th-century beginnings in France through its evolution and on to its American manifestations in the early 20th Century. Some especially helpful text, for instance, focuses on the French Barbizon painters, who in the 1840s left their studios and began to paint on location in the Forest of Fontainebleau, about 35 miles southeast of Paris — forever changing the development of landscape painting. Among the highlights: Courbet's raw, turbulent Marina, La Vague (The Wave) (c. 1869); Louis Breton's Fin du travail (The End of the Working Day) (1886-87), with its trio of weary workers set against a blazing sunset; and Hassam's elevation of the ordinary into the sublime in A Back Road (1884). Be warned, though: If you're among those for whom one landscape looks pretty much like the next, there's nothing here that's likely to convert you. If you're already a believer, however, you'll find plenty of sustenance.