When he was an old man, Turner often harked back to the long, arduous journey he made back in the summer of 1797, up into that part of the country described by Daniel Defoe earlier in the 18th century as the wildest, most barren and frightful landscape in the British Isles. The 21-year- old artist and would-be Associate of the Royal Academy travelled up through Rotherham, Doncaster, Pontefract, Wakefield, Durham and North Shields until he reached Berwick-upon-Tweed; he then turned back, travelling through Jedburgh, Carlisle and the Lake District before slowly winding his way back to London via Lancaster, York, Beverley and Louth. It rained a lot and crops everywhere failed. But the landscape did not seem barren to Turner. In retrospect, he came to associate the places he visited that summer with the first maturing of his sensibility. He certainly seems to have talked about his journey in such terms to John Ruskin, who gave a greatly sentimentalised but perhaps not entirely fanciful account of its significance to Turner in Volume 5 of Modern Painters.
"And at last fortune wills that the lad's true life shall begin; and one summer's evening, after various wonderful stagecoach experiences on the north road, which gave him a love of stagecoaches ever after, he finds himself sitting alone among the Yorkshire hills. For the first time, the silence of Nature around him, her freedom sealed to him, her glory opened to him. Peace at last; no roll of cart-wheel, nor mutter of sullen voices in the back shop; but curlew-cry in space of heaven, and welling of bell- toned streamlet by its shadowy rock. Freedom at last. Dead-wall, dark railing, fenced field, gated garden, all passed away like the dream of a prisoner; and behold, far as foot or eye can race or range, the moor and cloud. Loveliness at last. It is here then, among these deserted vales! Here is something God has made which no one has marred. Pride of purple rocks, and river pools of blue, and tender wilderness of glittering trees, and misty lights of evening on immeasurable hills."
The son of a Covent Garden barber, long pent up in the city, is released into Nature, where he finds not only a beauty he has never known before but finds himself, too: this is biography transmuted into Bildungsroman, but for all that it does not ring entirely false. It is plain that something momentous happened to Turner, in the summer of 1797, in the landscape of northern England. But whether or not it happened in Yorkshire, and whether or not it was attended by such Ruskinian intimations of divinity as Ruskin supposed, we can only guess.
As a draughtsman known for specialising in highly finished, extremely competent presentation watercolours of architecture, the youthful Turner almost certainly decided to set out on his journey north in order to expand his repertoire of topographical subjects. Wherever possible, he stopped to sketch ruined abbeys, castles and other sights well calculated to appeal to the late 18th-century taste for the picturesque. In many cases he perfected the dilapidation or the romantic grandeur of what he found, making Durham Castle and Cathedral from the River Wear, for instance, tower over the surrounding scenery rather more impressively than they do in reality. Turner, who appreciated the necessary artfulness of art, may have been moved to such adjustments and enhancements of the raw world by the writings of the Reverend William Gilpin, foremost formulator of the picturesque aesthetic. Gilpin advised artists to modify reality when it was insufficient to their purposes: "The imagination is apt to whisper, What glorious scenes might here be made, if these stubborn materials could yield to the judicious hand of art ... By the force of this creative power an intervening hill may be turned aside; and a distance produced." The judicious hand of Turner's art also often contrived echoes of the artfulness of others. His watercolour of The Refectory of Kirkstall Abbey combines elements of Piranesi and Rembrandt to good effect. The vaulted gloom of it is pierced by shafts of sunlight; dark decayed Gothic masonry, yellowed, comes to resemble crumbling cheddar.
Turner also stopped off during the course of his tour at Harewood House to make some pictures of that stately pile and its grounds for its owner Edward Lascelles, who later decided - presumably on the basis of works like the very carefully worked-up Harewood House from the North East - that Turner "finished too much" and "effected his purposes by industry". Lascelles preferred the watercolours of Turner's friend and contemporary Girtin, whom he considered a genius for the lightness of his touch; but Girtin died young, leaving the field clear for Turner, who proved genius of his own.
Lascelles' response to the watercolours of Harewood House now seems sensitive and fundamentally correct, insomuch as works such as these - and indeed many of the other predictable topographical watercolours in the artist's 1797 sketchbooks - have a certain by-rote quality. They adhere to well- tried compositional formulas, and there is nothing greatly original or distinctive about the codes employed in them to depict natural phenomena such as the fall of light or the movement of water. They might contain the odd hint or portent of what Turner was to become, but they are in essence apprentice works. It is not to them, but to the works in which we can sense Turner taking himself by surprise, that we should look for signs of something like the epiphany described by Ruskin. On the evidence of the Tate's exhibition, and David Hill's book, that epiphany took place not in Yorkshire but in Northumberland; and not at the end of the day, after a long journey, but at dawn.
Early one morning in September 1797 Turner, having reached the northernmost point on his tour into the North of England, found himself beside the River Tweed looking upstream. The imposing ruins of Norham Castle, perched on a craggy outcrop of rock a mile or two away, struck him as an impressive subject and he began to make a detailed pencil sketch of the scene. As he did so, however, the sun rose higher in the sky, and soon he found that he was being nearly blinded by its radiance. He abandoned his pencil sketch and decided to return to the theme at the moment when he had left it, but this time using the medium of watercolour.
Turner eventually made four watercolours of Norham Castle, Sunrise and they are among the masterpieces of his very early career. They are pictures of Turner's experience of almost being blinded by the sun and then realising - this, surely, was his 1797 epiphany - that the blinding sun moved him, as a subject, more profoundly than any other. The pictures in question continue to breathe the sense of excitement and discovery that Turner clearly felt when he painted them. The effects of luminosity achieved in these four watercolours are still as dazzling as Turner originally meant them to be. They are far more delicate and original, at the level of their technique, than anything else in Turner's uvre of the time - as so often in art, the compulsive need to express a previously unexpressed feeling has produced a revolution in the technical means of art.
Turner never forgot Norham Castle, and the place took on a special significance for him that increased with the passing years. In his book, David Hill tells the story of the painter revisiting it in 1831 while on his way to Scotland to make some illustrations for the work of Sir Walter Scott. Turner's travelling companion, Scott's publisher Robert Cadell, noticed that as the coach passed the castle Turner took off his hat and made a bow. When Cadell asked him why he had done this, Turner replied: "Oh, I made a drawing or painting of Norham several years since. It took, and from that day to this I have had as much to do as my hands could execute." That may make Turner's affection for Norham sound rather more offhand, and more exclusively worldly than it was. It is certainly true that the watercolours he produced were very favourably reviewed when he showed them at the 1798 Royal Academy annual exhibition; and those reviews certainly helped to launch Turner's career. But the change that the experience of painting those four watercolours caused in the life of the artist was (and no one knew this better than he) much more than merely financial. On the banks of the Tweed he had sensed what was to be the subject of his life's work. It was light: light viewed not as a mere source of illumination but as the very stuff, the essence, of the universe; light majestically proclaiming its own eternity, and the transience of all human creations, as it shines through a ruined man-made monument, making massy stone look as delicate as lace or fretwork.
It is extraordinary how many times Turner was to repaint, to vary and to modify the central theme of his early Norham Castle, Sunrise watercolours. The motif of a backlit ruin consumed by light or flames would always obsess him, because it expressed, so clearly and so perfectly, his fatalistic sense of man's ultimate destiny, while also allowing him to conjure up again that which he found most affecting and beautiful in the world. (For example, Turner's very greatest watercolours, painted more than 30 years later, in a very different context and on a very different theme, The Burning Down of the Houses of Parliament, distinctly echo the early Norham Castle works.) At the very end of his life, as if to emphasise the importance of Norham Castle to him, Turner devoted one of the most remarkable, incandescent oil paintings that he ever painted to the theme. He called it (what else?) Norham Castle, Sunrise. The castle, in fact, has all but disappeared, present only as a flicker of stony insubstantiality atop a hill that is really just an exhalation of blue. The several cows in the early watercolour have become one ghostly brown bovine blur. Matter has dissolved to colour in this shifting world, and the play of light is all. The sun shines brighter than it ever did, in this painting of a memory charged with feeling, this old man's recollection of the bright dawn that first revealed him to himself, all those long years ago, by the side of a river near a castle in Northumberlandn
`Turner in the North of England, 1797', is at the Tate Gallery, Millbank, London SW1 to 9 Feb 1997. Information: 0171-887 8000