TWO 20th-century British artists were known for their mannerisms in dealing with the human figure. L.S. Lowry was famed for his matchstick men. William Roberts’s speciality was his tin-can men, their arms and legs rigidly tubular. In the background of this major show, though never quite spoken, is a question: Lowry is as famous as ever, but hardly anybody remembers Roberts. Why?

Well, for a start Roberts was a notoriously awkward customer. (Lowry’s oddity was more socially manageable.) He disapproved of the art market and all dealers, so he refused to show in public except at the Royal Academy Summer Exhibition. To make matters worse, his son John died intestate, and the artistic legacy has been in limbo, unavailable for loan, even to the present show.

Happily, this new retrospective makes it clear that he does not deserve such a fate. True, some of the later paintings, such as Goal (1968), go beyond what is readily acceptable even as lovable eccentricity, so bizarre is it collision of violent football action and statuesque immobility. But even that, like Roberts’s contemporary pictures of hippies in the King’s Road, somehow niggles at the brain. It is intriguing that a survivor from the early days of Cubism should be moved even to try such subjects.

For that is just what Roberts was. The Hatton show enables us to chart his progress from rather stolid, academic beginnings at the Slade before the First World War, through his rapid progression towards modernism.

The great new movement in British art of the day was Vorticism, with its tendency towards abstraction, its worship of the machine. What Roberts had learnt from it he carried into his experience as a field gunner in the war itself. His war pictures are among his most powerful: the experience affected him deeply, and one suspects that his Vorticist background gave him the pictorial language with which to discipline the raw emotion.

After the war, the retreat from too much contact with his fellow men also begins. The everyday experiences are observed: people in the theatre or the cinema, women beating carpets, a shoe-black, plying his trade on a domineering woman. There is a mordant sense of humour, whether in an image of dons disporting themselves naked in Parsons’ Pleasure, or of the London Group of artists giving a stiff-necked reception.

The effect of a whole retrospective devoted to Roberts can be maddening, but it is also curiously bracing. His vision was definitely weird, but no more so than Lowry’s. His ideas of composition, often with strong verticals which divide a picture like Trooping the Colour (1959) or The Lake (1964), follow rules one cannot even guess at. He remains one of a kind. But certainly not the non-person he has become in the quarter-century since his death.

• William Roberts, Hatton Gallery (0191-222 6059), until May 29