Nature's Engraver, by Jenny Uglow

Returning from Harwich to London by train, I noticed an incongruous figure among the suits, summer dresses and T-shirts waiting on Marks Tey station. This was a young man dressed in the medieval costume of the Gesellen, the German journeymen: black slouch hat, white-buttoned jacket and pantaloons, rucksack and walking staff. The 18th-century artist, Thomas Bewick, would have been delighted. A central motif of many of his wood engravings is the tramping artisan, the itinerant musician or dancing master, journeying through life. The form and attitude of the traveller's body tells much of the story, the trees and woods beyond, the rest. Every vignette embodied a moral statement, suggested by the crack in the wall of a landed estate, or a gibbet in the distance hinting of a fate foretold.

Jenny Uglow's affectionate biography gives us a Bewick whose interests and complex political sympathies speak to our times: a patient observer of the natural world, a concerned family man, an entrepreneur and radical, and someone who could sum up a colleague with a single word: "Kindness". The book is worth buying for the reproductions of Bewick's engravings alone. His genius lay in transforming a popular genre - the hand-carved woodcut - into an art of miniaturist delicacy and narrative precision. Wordsworth wrote that he would give up verse and prose to be able to draw like him.

Bewick started by inscribing trophies and gift-boxes, as well as designing visiting cards and playbills, going on to sketch and then cut scenes and incidents from provincial life. His boldest move was to dispense with the traditional solid border, so that the dynamic structure of the illustration emerged from the subject, free from all constraints. Bewick achieved for graphic illustration what William Kent had done for landscape design, when Kent dispensed with the borders of the formal garden, and "leap'd the fence". This freedom of the subject matter to set its own boundaries became one of the defining characteristics of English art and landscape.

Fame arrived with his books of engravings of animals and birds - Quadrupeds, Land Birds, Water Birds - which transformed popular knowledge, and helped create a change in sensibility towards the animal world. His era debated whether animals had souls, today we discuss whether they have rights. An earlier tradition of crude woodcuts of animals representing simplified moral virtues was given almost palpable life.

Bewick was also regarded as a hero of the self-educated culture of the "freeborn Englishman", committed to liberty and sensible to the rights of others. His early sympathies for American and French republicanism led to fears for his own safety at home. He remained a friend of the ultra-radical Thomas Spence all his life, though disagreeing with Spence's insurrectionary views.

As with all Jenny Uglow's books, there is the now familiar blend of painstaking research and historical erudition, combined with a sympathetic engagement with the family life of her subjects. Bewick lived in interesting times. The son of a farmer and mine-owner, he grew up during the early Industrial Revolution, in times of political revolution abroad, but also during a revolution in natural history, equally "from below".

He contrasted the living knowledge of the field naturalists - mainly farmers and artisans - with the rarefied knowledge of "garret naturalists" who stayed in their rooms. His animals, birds, trees and plants, were drawn from nature, their habits deduced from folklore and observation. A kind, anxious, brilliant man, he was not without wit or mischief, illustrating the maxim, Esto Perpetua (Let It Endure For Ever), with an engraving of a snowman.

Ken Worpole's 'Last Landscapes' is published by Reaktion