The British painter Ben Nicholson, whose first American retropspective opened last night at the Hirshhorn, is a much traveled man.

He traveled and painted not only in obscurely romantic places like Holkham Sands and Towednack on his own native isle, but also in Spain, France, California, the Adriatic and the Baleares.

And he traveled erratically, it seems, from Braque to Picasso to Miro to Jean Arp and Juan Gris to Mondrian (a bad trip) back to Braque again. There was at least a brief stop with Paul Klee's whimsy, to refuel his lighthearted fantasy, it would seem.

But in the last decade or two Ben Nicholson, who was born in 1894, appers to have settled down.

He has settled down to bold, large reliefs of haunting shapes in lyrically muted colors. They have a kinship with Henry Moore's sculptures.

These truly Ben Nicholson Nicholsons are at first glance as abstract as his white-on-white geometric reliefs of the 1930s and '40s that keep confronting circles with squares. But these more recent reliefs bear out his statement that "however 'non-figurative' a painting may appear to be, it has its source in nature."

The Nicholson Nicholsons have such titles as "Delos" or "Valley between Rimini and Urbino" and if you let these works sink in, you can perhaps not see, but feel the Greek island or the Italian landscape.

Surely then, this one-man anthology of the modern movement is not only a splendid british artist, he is a great artist. We should be grateful to the Hirshhorn for showing us his works on paper that represent 50 quainted.

We must also applaud the Hirshhorn for giving such a sparkling display to the nearly 70 paintings and 15 works on paper that represent 50 years of Nicholson's art. Nicholson's unique sense of color is enhanced by the fresh pastel hues on some of the exhibit walls. It is something of a break-through in exhibit technique.

The exhibition has been drawn from more than 40 collections, was organized by Stephen A. Nash of the Albright-Knox Gallery in Buffalo. and will continue through Feb. 18.