James Kelman, 11.30am ***** Dan Cruickshank, 1.30pm *** Every now and then the Book Festival, where normally feathers remain studiedly unruffled, springs splendidly to abrasive life. For this we have to give thanks to James Kelman whose every appearance brings with it the frisson of the unexpected.

Of late rumour has it that, now he's in his seventh decade, Scotland's only Booker Prize winner has mellowed, that he is chilled. If that's so then it must have been an impostor who appeared yesterday.

Kelman's temperature began to rise when he talked about the release of Megrahi. There was something "weird", he said, about hearing the BBC refer to "the struggle for democracy in Afghanistan" while at the same time the Scottish government was being "slated" by the FBI for taking a decision entirely within its rights. Irony is an insufficient word to describe the absurdity of this. Kelman personally believed that the guilty verdict Megrahi received was unsafe and that by allowing him to go home to die the government was tacitly acknowledging this.

He was then asked about how politically involved Scottish writers are today. Not a lot seemed to be his best estimate. Certainly not as engaged as he and others were at the fag-end of the 1980s in the run-up to Glasgow's Year of Culture in 1990, when there were plans by the council to sell off a third of Glasgow Green.

The received wisdom now, said Kelman, is that 1990 was a success. If it was, then it was bought at a cost of £50 million.

This, though, was simply the warm-up. Kelman said that in articulating opposition to such moves he and other writers were acting in a Scottish tradition. In behaving thus, he said, he could take the criticism from outwith Scotland. It was that from within, he suggested, that sent him into a froth. The reaction of the Scottish literary establishment was to sneer at him and his ilk.

"For me," he said, "it's always been an indication of that Anglo-centric nature of what's at the heart of the Scottish literary establishment that they will not see the tremendous art of a writer like Tom Leonard for example, and how they will praise the mediocre, how so much praise and position is given to writers of genre fiction in Scotland."

Quite how this manifests itself he did not explain. But there is among literary writers such as Kelman, who is widely regarded as Scotland's greatest living novelist, a growing resentment over the championing and ubiquity of popular writers such as Ian Rankin, Alexander McCall Smith and JK Rowling.

"As I argued recently," Kelman added, "if the Nobel Prize came from Scotland they would give it to a writer of f***ing detective fiction or else some kind of child writer or something that was not even news when Enid Blyton was writing the Faraway Tree because she was writing about some upper middle class young magician or some f***ing crap."

Prior to this Kelman read a 25-minute "peroration" from Translated Accounts, one of his lesser known novels. Written in the first person, it tested the audience's patience, which is no bad thing, for too often at the Book Festival writers aim simply to please. Having said all that, it sounded like one of Fidel Castro's speeches would if it was translated by John Prescott.

Dan Cruickshank is to igloos and yurts what David Attenborough is to iguanas and yaks. His latest jaunt, underwritten by licence fee payers, was a trip which embraced five continents and 20 countries, the object of which, said Cruickshank - apart from a TV series and a book - was to relate the history of architecture.

To this end he visited the Inuit, one of whom he persuaded to construct an igloo. For anyone thinking of trying this you need to access the right kind of snow. You should also not attempt to build too big an igloo. One storey is your limit. As the Handy Andy of the Inuit set to work, local children watched in wonder because they had never seen anyone build an igloo before. Nor, one suspects, will they want to do so again. The igloo he made looked like the kind of shed you see on an allotment.

Cruickshank is the personification of the endearingly barking Englishman. Words tumbled out of his mouth like smalls from a drier. Sentences remained unfinished. He waved his arms and flapped his hands as if trying to shake them off. Yet before he went on his travels his minders at the BBC told him to play "the grey man", to melt into the background, lest he be blown to pieces or abducted.

His message - all pluggers must have one - is that the great architectural treasures of the world, from Machu Picchu to the Valley of the Kings, are under threat because we - prompted by him - insist on visiting them. Chance would be a fine thing.