John Walker's abstract paintings, now at the Phillips Collections, are fine and muscular. Walker is an Englishman, he is now a fellow at Oxford University). and while there is something quite un-British in their bigness, fineness of his pictures - their colors and elegant correctness - what surprises is their power. There is something quite un-British i their bigness. The feeling that they were painted by a giant with big brushes and big hands.

Walker draws with his whole arm. He paints with odd materials, not just oil paint, but powdered pigments, sand and thick, transluscent gels. His pictures are colleges. He cuts shapes out of canvas - rectangles, truncated triangles and a shape that is an oval cut off a both ends - then he paints arranges and glues them to the picture. Their edges, arcs and angles produce a sense of harnessed movement. Look at them awhile, and these strong shapes start to work; they rotate, pause and swing like cogwheels and piston-arms of some powerful, complex, industrial machine.

Yet despite their strength and size (some are ten feet tall), Walker's paintings neither bludgeon nor shock the observer. There is something like politness in the way they acknowledge other abstract painters (Schwitters, Diebenkorn, Matisse) and other art traditions.

In recent years, the Phillips has acquired three large English pictures; one is a Ben Nicholson, the other two are Walkers. All three display carefully composed arcs, straight lines and planes, but beside the Walkers, the Nicholson seems timid, enervated, gray. Walker surely is among Europe's finest abstract artists. His show closes

Though "Autobiographical Art History," the title of Leslie Kuter's show now at Fraser's Stable, Rear 1910 S St. NW., is accurate enough, "Catchers and Old Masters" would fit it just as well.

The masters represented include Vermeer, David and Eakins, Tischbein and Giorgione, Duchamp and Degas. Among the accompanying catchers are Jackie Hatt of the Giants, Steve Korcheck of the Senators, Ty Cobb of the Tigers and Moe Berg. the Princeton-educated baseball-playing spy (who asked, "How did the Mets do today?" seconds before he died).

Certain strong and evocative shapes catch Leslie Kuter's eye. She likes Duchamp's mysterious "Chocolate Grinder," Degas' bathing nudes, Audubon's swooping eagle, Vermeer's rear view self-portrait and Tischbein's Goethe lounging in the Italian sun. These familiar images, borrowed from art history, have been reproduced in her strong and witty works. Also she likes catchers.

She likes the shapes they assumes as they squat behind the plate (or, in the case of Cobb, steal second base). She likes their metal masks, their large, receptive mitts. What is nice about the catchers in this Old Master context is how splendidly they fit.

Kuter's collage-like pictures are not painted, they are hooked; all are made of scavenged stripes of cloth. She has somehow managed to duplicate, in wool, the pastels of Degas, Tischbein's 18th-century brushwork and the gauzey-yet-precise focus of Vermeer. Her delightful pictures are intelligent, striking and they activate the wall. Her show closes June 17.

Washington's Robert Gates, who taught for many years here, first at the Philips Collection, later at American University, must have been a fine and undogmatic teacher. One sees that in his art. Gates, whose work is now on view at the Jack Rasmussen Gallery, 313 G St. NW, seems to teach - and learn - in every work on view.

He could paint expressionist abstractions and formally composed still lifes, flowers, seascapes, sun. Also he made prints. His extraordinary range is seen most clearly here in the small drawings on view.

Most were done in life class - the model is the usual plump and stolid nude - but there is nothing heavy in the way Gates draws. his sensibility is delicate. His line is always fresh, accurate and free. These pictures seem the work of a studios explorer - they owe something to Matisse, to the Impressionists at the Philips and also to de Kooning and they do not deny their debts. The artist's health is poor now, Gates no longer paints. The pictures on display date from the 40s through the early '70s. The best of them - the life drawings, the locked-in quiet still lifes and sky-filled landscapes, still seem vital. The show closes July. 1.

Reeve Schley, whose watercolors are on view at the Hull Gallery, 3301 New Mexico Ave. NW., paints spacious, charming landscapes full of air and winter light. There is no medium more demanding, errors, cannot be corrected, the light that makes these watercolors fail or succeed is almost aways cast by the whiteness of the paper, rather than the paint.

Schley is at his best when he shows pale things, cloud-reflecting tide pools, snow in drifts, or thawing, pale winter skies. The pictures on display look best from a distance. Seen close up, his trees, seem awkward and too clumpy, they have arbitrary branches. His brushworkis less fine than his sensibility. His show will run through June.