Since the American showman David Blaine believes himself to be the new Houdini, it follows that he should, like his more gifted predecessor, have decided to bring his tricks to London. It was, says Ruth Brandon in her biography of Houdini, the reception of his manacle escapes on the London stage that confirmed his "uttermost hopes and expectations". Houdini became so famous here, she adds, that Lord Northcliffe, the newspaper proprietor, visited his dressing room, asking advice on various topical events. And who knows? If Blaine's new stunt - "his toughest endurance feat yet" - comes off, maybe our own newspaper proprietors will soon be seeking enlightenment from this most sapient of nappy wearers. At the time of writing, however, it seems unlikely. So far from confirming his uttermost hopes and expectations, Blaine's encounter with the British public appears to have been his first ever encounter with sustained derision. After two days in which the magician came under assault from fish and chips, eggs, golf balls, laser pens, wake-up calls from bhangra drums and women displaying their breasts, a spokesman for Sky television, which has bought the rights to this stunt, regretted that not everyone had been "respectful to the challenge... unfortunately you will always get one or two thugs". But the antics of these one or two had been enough to frighten Blaine's organisers into surrounding his crane-and-dangling-box arrangement with some untidy wire fencing. Now, with its profusion of electrical wires, tents and heavies, his "Above the Below" encampment below Tower Bridge looks about as edifying as the back end of a funfair.  Still, should you be looking for an agreeable picnic spot, I can think of no better place, just now, than below the above: the area of dusty, trodden-down prairie over which Blaine now languishes for a living. Not because the magician himself is much to look at. In a few weeks time, when he begins, like all ill-nourished down-and-outs to resemble someone who could be Lord Lucan, it might be different. For now, the visiting daredevil simply looks greasily out of sorts, podgy enough to last several weeks, and seems to share Tony Blair's lack of inhibition about yawning and picking at himself in public. No, the place is worth a detour not in order to admire Blaine, but to participate in an exhilarating act of collective ridicule. If you can take some food with you, so much the better. If not, I have discovered, even a blob of oily ice cream from the van tastes exquisite when consumed in the suspended company of the preposterous, faux-starving Blaine.  Improved security had done little, when I visited, to bring about the desired reverence for Blaine's very public diet. And the previous night's adulatory C4 documentary, in which the visitor proclaimed, "I'm an artist, nothing more, nothing less," probably hadn't helped, even if it had attracted more people. Anyone who remembered Blaine's parting speculation about his chances - "Will the air supply suddenly get cut off and cause suffocation... even death?" - had only to look up to realise that the simple answer to this question, was, no, it wouldn't. You'd think he would have known that. Not with those two little windows.  The disparities between the advertised, and real event were such that you wondered if there could have been some kind of mistake. Weren't Tower Bridge and the Thames meant to be somehow involved, instead of just picturesquely adjacent? And on telly, a wide-eyed Nicky Campbell had referred repeatedly to "solitary confinement". Blaine had also stressed a desire for "no distractions... I think that's the purest state you could be in... " In practice, he has made his lit-up box the pinnacle of a non-stop party. Passing riverboats and vans tootle jolly hellos at him. Women wave. Spectators guffaw more or less in his face, shout at him to "put the kettle on", mime flying with their arms, threaten to come back with signs reading: "Are you mental or what?" When, laboriously, Blaine wraps a sheet round himself and makes as if to wee into a hidden tube, there are uproarious shouts of, "He's having a piss!"; then, "He can't still be having a piss"; then, "No - he's wanking!"; then - after the business is seemingly complete - hearty cheers and applause.  Next, in his solitary confinement, Blaine takes up what we know, from Campbell's breathless tribute, to be "his journal". "Day one," says a man behind me, "Sat in a glass box." "Day two, still sitting in a glass box. Day three... "  Paid observers inform us that after a while Blaine's body will begin a metabolic process known as "ketosis", in which, if I understand correctly, it eats itself for breakfast, lunch and dinner. A   year or so ago, this might have sounded quite awful and impressive. Alas for Blaine, one in 10 Britons have now learned from Dr Atkins that ketosis is in fact a "wonderful process" - that beatific stage of the slimming regime when the dieter begins to burn his own fat reserves, and so starts to become a lovelier, more streamlined person. Lucky Blaine! For different reasons, people who have been unable to eat because of advanced illness, and their relatives, may also find themselves indifferent to Blaine's agonies. If agonies they are. Though, being notably well covered, he seems unlikely to be as indifferent to food as Kafka's hunger artist, who never found any food that he liked, as Blaine's task is presumably made easier by the 5m he will earn from this episode of professional fasting.  Aside from micturate and attend to his journal, Blaine also waves for the cameras, turns over to show his tattoo, moves his sheet around, scratches his head and, from time to time, fills a water bottle from another tube. These actions are duly texted, photographed, reported and filmed on mobile phones - mostly redundant devices which seem almost to have been waiting for this still more redundant event in order to prove that they may, after all, occasionally serve a purpose: "No, he's just sitting there, no, he hasn't moved, no, it's really funny... "  This was not, you gathered from the Blaine programme, the intended response to ostentatious fasting, an act repeatedly introduced as "his toughest endurance feat yet". The crowd are supposed, like the American multitudes before them, to faint with anxiety, empathise through the long nights, discern some noble purpose in his supposed travails in the ice, up pillars, inside glass containers. Instead they watch, eat and cackle. To anyone who has recently felt downcast by popular displays of credulity and celebrity worship, this massed derision should come as a reassuring, even an inspiring, sight.  In fact, the prospect of Blaine at the mercy of a good humoured, but predominantly satirical crowd, composed of visitors of all ages, classes and ethnicities, hints at some residual, collective good sense, which can tell the difference between a huckster and a hero, and thus differentiates us from Americans. If Blaine could be induced to stay, for all time, in his silly box, there could be many worse ways of acquiring British nationality by composing some appropriate insult in the English tongue, then throwing an egg at him.