Painting 'as a child paints'

There's something indelibly English about the watercolors of Eric Ravilious. They certainly don't belong to the sun-drenched Mediterranean. Their luminous mistiness and muting of all vivid color is distinctly northern and cool. Yet this quiet grayness of tone is surprisingly intense. "The Vale of the White Horse" - one of a series of paintings he made in c1939 of chalk figures cut in the landscapes of southern England - beautifully epitomizes his style, its mix of softness and hardness. Critic Eric Newton observed: "All the qualities dear to watercolourists - a full flowing brush, a facile exploitation of the charm of the medium - are nothing to [Ravilious]. He paints as a child paints, obsessed with meaning."

In fact, the "meaning" of the Bronze Age Uffington white horse, cut out of turf on a gently rounded brow in the Berkshire Downs, is obscure. The 375-foot-long ancient figure is schematic and symbolic - and indeed childlike. It's quite difficult to see except from the air.

The appeal of these chalk figures to Ravilious is obvious. He was a wood engraver - a skilled contributor to the early 20th-century revival of this printmaking technique. Engraving involves cutting into the surface of a boxwood block, each cut resulting as a white mark or space in the final print. The Uffington horse is like a gigantic "cut" into the surface of the landscape.

Ravilious was a book illustrator. He knew the difference between realism and stylization. His watercolors are not photographic. They are re-creations in terms of line, texture, tone, and color, and make no effort to disguise the fact. This English artist's linear exactness is not unlike that of the Precisionists in America. He was similarly fascinated by the complex structures of buildings and machinery. Everything is precisely edged. Ravilious could bring his style to bear on the shadowy undulations of a high, bare landscape, infuse it with atmosphere, and suggest with striations and crosshatching the sparse grasses up there as well as the imminence of rain - or sunshine.

• This painting is featured in an exhibition at Tate Britain until Sept. 4 called "A Picture of Britain."