Undersized, jowly and corpulent, Turner, as Hamilton admits with a defensive smirk, was "no oil painting". In his self-portrait he flatters himself physically, as well as awarding himself a social promotion by impersonating a gentleman traveller. Ashamed of his inauspicious Covent Garden birthplace, Turner moved his studio to Harley Street, where his expert milking of the collectors made him, Hamilton calculates, a millionaire in today's terms.
Critics taunted him with coded reminders of his lowly origins, sneering that his landscapes resembled a greens stall and likening his human figures to sacks of potatoes. Turner consoled himself, according to Bailey, with fantasies of "imperial ambition". He painted the triumphal career of Aeneas and brooded over the fate of Napoleon, whose irresistible energy threatened ancient social prejudices; a property deal was for Turner, as Bailey puts it, "empire-building" on a smaller scale. Bailey's book concludes with a study of the grandiose will in which Turner, bequeathing his paintings to the nation (and specifying that he must be buried wearing one of his rolled canvases as a shroud), transformed himself into a national treasure. Hamilton, on the other hand, concentrates on Turner's Wordsworthian feats as a walker. On his sketching tours, he covered an average of 20 to 25 miles a day.
The biographies concur in their view of Turner's achievement. He painted light in a new, mystifying, often glaringly vivid way. Both emphasise his daring by comparing him to Regulus, imprisoned in a dark room where his eyelids were sliced off, then exposed to a sun whose brightness blinded him. Bailey's title underlines this obsession with the incineration of the natural world: the "angel standing in the sun", painted by Turner in 1846, is a harbinger of apocalypse from the Book of Revelation. Hamilton frames his life within solar annunciations. Strange haloes multiplied the sun in the week of his birth, and as he died a freakish mid-winter aureole lit up his room. On his death-bed, he remarked "The sun is God" - though Hamilton admits that he may have more piously meant that "The Son is God", while Bailey discounts the story altogether and claims that Ruskin made it up. Turner called his country house Solus Lodge, which makes it, for Bailey, a resort of self-proclaimed solitude. Hamilton, aware that Turner's spelling was erratic, over-cleverly proposes that "the Latin for the genitive case of `sun' is solis, a word Turner will have known even from his fractured classical knowledge".
The paintings, as Constable said, were "golden visions". But the biographers believe they were conjured out of Turner's psychic gloom. His technical innovations provoked accusations of madness. Hamilton, intrigued by the narcotics and purgatives with which Turner dosed himself, calls him a hypochondriac and suspects him of suicidal yearnings. Bailey wonders if the reviewer who laughed at Turner's sulphurous yellows as "jaundice on the retina" might inadvertently have spoken the truth: were his chromatic hallucinations the signs of some ophthalmic disaster?
Contemporaries thought of Turner as a magician, a "Prospero of the graphic arts", and Turner encouraged this notion. He claimed, quite implausibly, that he had himself lashed to a steamboat's mast so he could study a snowstorm at sea. He even named the vessel, calling it the Ariel; neither biographer can find any record of its existence. He was also likened to the violinist Paganini, who derived his technical virtuosity (or so superstitious whisperers alleged) from a pact with the devil.
Hamilton, generally sceptical about rumours and legends, refuses to speak ill of Turner. While Bailey jocularly documents the squalor of his studio, overrun by incontinent cats, and remarks on his unswept chimneys, Hamilton believes that the numbered labels on Turner's sketchbooks attest to his "innate tendency for tidiness". The notes Turner made for his Royal Academy lectures on perspective convince Hamilton of his valiant efforts "to get both his written and his spoken style into some kind of order". For Bailey, the tortuous syntax of Turner's letters and the muddle of his poetry look like symptoms of emotional inarticulacy, or perhaps dyslexia. The struggle to regulate thoughts, acclaimed by Hamilton, strikes Bailey as a sign of schizophrenia: "frequent Jekyll and Hyde tussles went on in his brain". Bailey teases Turner as a Scrooge; Hamilton acclaims his "wonderful flashes of generosity". In retaliation, Bailey points out that his affections were only institutional. Having presented his fellow-academicians with 12 silver dessert-spoons, he "went on being more generous to the Academy than to any of the women in his life".
The smallest incidents can prompt opposed verdicts. On a trip through the West Country in 1813, Turner told his companion "I am a Devon man," vouchsafing that he came from Barnstaple. In fact he was born in Maiden Lane, a scummy alley north of the Strand, named in homage to the prostitutes who plied their trade in it. Bailey begins his book with this story, because it shows up Turner's self-aggrandising mythomania. He falsified his place of birth and (in the absence of other evidence) was free to fictionalise his birthday: he declared that he was born on 23 April, sharing the date with Shakespeare and St George. When the Barnstaple story crops up, Hamilton neatly finesses it. Turner, he insists, was professing an affinity with the landscape. Why make a fuss about it, when we don't mind President Kennedy announcing "Ich bin ein Berliner"? Visiting Rome in 1819, Turner coincided on the Capitol with the Princess of Denmark. A stiff wind incommoded the princess, and a soldier grabbed Turner's umbrella to shelter her from it. The umbrella was blown inside out, and snapped some of its ribs. "Turner scowled," reports Bailey. Hamilton, however, justifies his annoyance by supplying extra details: it was "an expensive umbrella, with a two-feet- long dagger hidden in the handle to guard against felons" - an essential precaution for the Englishman abroad.
On the crucial relationships in Turner's life, his biographers are systematically at odds. The family packed off Turner's mentally turbulent mother to an insanitary and punitive public asylum, even though they had funds for private care. Bailey calls the decision "cheap, mean-spirited and unloving", and speculates that Turner had other reasons for wanting the poor woman out of the way. Did he fear that her malady might be a hereditary doom? Hamilton, more guarded, remarks only that the confinement "was shabby to say the least", though he guesses that some obscure sketches of grappling captives may be "sublimations of his mother's trials". Both writers acknowledge Turner's devotion to his father (who also served as a grateful slave). Bailey quotes an apologetic note, written at the last minute to cancel another engagement, in which Turner pleads an urgent trip to Twickenham for his father's 70th birthday. "Tersely eloquent", it testifies to this shy man's capacity for love. Hamilton downplays the bond - "he had a son's normal concern for his father" - and takes the same note as evidence of Turner's "driven nature" and his habit of double-booking himself. Bailey castigates Turner for neglect of his children, while Hamilton flimsily pardons him on the grounds that he painted "The Tenth Plague of Egypt", suggesting he worried about "dangers to children".
Bailey and Hamilton also diverge on Turner's elderly liaison with the Margate landlady Mrs Booth. He secretly cohabited with her, adopting the name of her late husband as an incognito. Neighbours took him for a retired admiral, and fondly nicknamed him Puggy Booth. She looked after him in his final illness, spending her own money - despite his wealth - in the process. Bailey treats the episode as an exercise in Bunburying, disclosing Turner's talent for subterfuge while making clear his sexual appetite, and has no doubts that Turner warmed the widow's bed. Hamilton is more delicate. He insists that Mrs Booth played a "motherly role", since Turner's only "darlings" (by his own admission) were his paintings, and he absolves the couple of "any intention to deceive ... or to run a double life".
Yet how can either Hamilton or Bailey know what went on behind closed doors, or inside locked and bolted heads? Occasionally they let their confident assumption of omniscience slip, and remind us that a biographer is one who affects intimate acquaintance with a long-dead stranger. Hamilton has a weakness for over-eager surmise, passed off with the aid of a collaborative plural pronoun. He imagines Turner's introduction to Lord Egremont's house at Petworth, "guided, let us suggest, by Egremont himself". The suggestion seems innocent enough, except that half a page later Hamilton, having lapsed into historical fiction and adopted the present tense of reverie, is making up dialogue for Turner's patron: "`You can paint in here, if you'd like,' says Egremont quietly in his Sussex brogue." Petworth, whose rooms were painted by Turner as pools of lambent light, also impels Bailey to indulge in a stubbornly fictitious whimsy (which he has the good grace to smuggle into a note at the back of his book). He argues that a picture formerly called "Interior at Petworth" was Turner's obituary for Egremont: through an impressionistic blitz of colour, Bailey identifies Egremont's "black-topped catafalque", near which a mob of yapping dogs maul a table- cloth. But the notes concede that the painting is no longer thought to be associated with Petworth; the Tate neutrally catalogues it as "Sack of a Great House". Bailey - licensing his own day-dreams, like Hamilton on that imaginary tour of the house - demurs: "partly because of the dogs, I prefer the earlier, Egremont-connected theory."
Bailey's is the better narrative, with the more compelling characterisation. He emphasises his subject's moral chiaroscuro, showing him to be a sun- worshipper with what Ruskin called a dubious "dark side". Hamilton has the sounder academic credentials: he was Nuclear Electric Turner Scholar at the Tate Gallery - a post which, in a small marvel of sponsorial ingenuity, co-opts Turner's heliocentric religion to boost the industry responsible for Chernobyl. The story is more soberly and reliably told by Hamilton, though Turner the man disappears into the paintings. You can take your pick. I have decided never to trust a biographer again.