Tales Of The City: Ulysses is on the left. (Apparently)

The outbreak of controversy over Turner's oil paintings is surely taking literal-mindedness to extremes. You remember that story? Ian Warrell, the curator of an exhibition on Turner and Venice at Tate Britain, recently inspected two 1845 oils called Festive Lagoon Scene, Venice and Procession of Boats with Distant Smoke, Venice, and worked out, to his own satisfaction, that they weren't views of Venice at all but of Portsmouth, and that they depict the arrival and departure of King Louis-Philippe of France in 1844. Mr Warrell can apparently make out, amid the mad swirls of orange, azure and white, and some dim figures in the foreground, the presence of British soldiers, "festive crowds" and the "distant smoke" of the King's barge.

Well, good for Mr Warrell. I'm sure he has all the sketchbook-and-diary evidence to back his claims that JMWT was celebrating Pompey rather than La Serenissima. But doesn't his intervention remind you, just slightly, of Lewis Carroll's poem about misidentification in Sylvie and Bruno? "He thought he saw an elephant/ That practised on a fife:/ He looked again and found it was / A letter from his wife./ 'At length I realise,' he said/ 'The bitterness of life'."

Even with an electron microscope, you'd have trouble finding any municipal landmarks amid the coils of impasto. I'm with the lady from Portsmouth tourist office, who, when asked if she could see the resemblance of the painting's muddy cloud-shapes to Portsmouth harbour, replied "I can't see any resemblance to anything."

I can't either, but that's hardly the point with Turner, whose experiments with the play of light, the blinding shimmer of sun on water, so empowered the Impressionists. Turner was interested in the shimmer, not the people or the public events that it eclipsed; his passion was to find how to express it in paint, if it meant piling on the oil two inches thick. So it's rather charming to find grown men in the 21st century struggling to discern the details of "what's going on" in a painting, and arguing whether the pink blob in the corner is a cherub or a cherry tart. But we do, don't we?

At the marvellous Lloyd Webber exhibition of Victorian oils at the Royal Academy, I gazed, entranced, at the London night street-scenes of the Yorkshire-born Atkinson Grimshaw, with their gas lamps, hansom cabs and shadowy pedestrians. I knew it was a triumph of technique, of darkness and points of light, and that's all it was, but I peered and peered, as through, were I to look really closely, I'd be able to see into the eyes of the ladies in veils and shawls, or spell out the name of the corner shop, or make out what the boys are carrying on the little barrow...

Art exists to trick us into thinking that we're seeing more than is actually on a canvas - more details, more dimensions, and more metaphorical truth. It's idiotic to try to pin the artist down over matters of who, where and what. But it's hard to look at an epic Turner work such as Ulysses Deriding Polyphemus and not say, like a child, "So where's the giant, then? What's that man doing waving a red blanket? Is that what 'deriding' means?" But I expect that, even now, Mr Warrell is looking through his notes, and will shortly rechristen the picture "Sailor Waving Duvet Cover to Attract Air-Sea Rescuers in Lake District"...

The art of cooking: a fitting tribute to Delia

Art is everywhere this week, what with the shock closure of Pharmacy, Damien Hirst's restaurant in Notting Hill. It was a good place, where the stools at the bar were mocked-up as giant white Aspirin tablets, but you could ask for a Holsten Pils all evening and get nowhere (and nor would anybody realise you were being uproariously witty). But the wild art-meets-food news is that Marc Quinn, who famously sculpted his own head out of nine frozen pints of his own blood, is to do a portrait of Delia Smith; he's been commissioned by the BBC, to celebrate her 20 years of making television programmes. I can't tell if it's a sculpture or a painting, but the portrait will feature stuff from her favourite recipes.

The mind boggles, doesn't it? Will he follow the example of Giuseppe Arcimboldo, the 16th-century artist whose faces were constructed from artfully arrayed plums, bananas and ears of corn? I think portraying the sensible Delia's face as a mosaic of cranberries, eggs and (just imagine) nine frozen pints of single cream would be most appropriate - and it would bring a rosy bloom to her pallid cheeks.

Brought to book

I came to the end of taping 20 shows in BBC 4's The Big Read: Battle of the Books with a heavy heart. Every week for five months, I stood in a mocked-up court of law pleading on behalf of a book from the Big Read list, interviewing its distinguished fans and scoffing at the claims, the taste and the witnesses brought by my rival advocate, Ian MacMillan, the droll Northern poet and comedian. I'll miss the convergences of witnesses backstage.

I've seen the sleepy and herbivorous ex-Heritage Secretary, Chris Smith, seethe with passion over The Grapes of Wrath, and the former Bishop of Edinburgh, Richard Holloway, coming on like JC Flannel in Private Eye about the need to forgive the racist bigots in To Kill a Mockingbird. It was nice to see Michael Portillo join forces with Rowan Pelling, the slinky editor of The Erotic Review, to speak for The Secret History (will he become her regular contributor?) And how weird to find myself playing a barrister - patrician sneer, thumbs under lapels - while asking Michael Mansfield QC to explain his interest in The Woman in White. Everyone we asked, no matter how busy, came out to argue for their favourite. Can it be that the study of literature, far from being an elitist pursuit, is, in fact, a democratic influence?