Mrs Maxwell, 71, who was billed as 'widow of the celebrated publisher', was greeted with warm applause by a full house in the marble splendour of the regency town hall. Looking tanned and radiant she spoke for an hour on her favourite subject - pausing only for a sip of water.
She denounced the infernal ballpoint pen, burbling letters and bleeping fax machines for eroding one of her greatest passions in life.
'Unlike the fleeting pleasure of the telephone call, letters can be kept forever, hoarded like jewels so their intimate secrets can be read over and over again,' she said. 'The absolute worst sin is to destroy them. It's my own conviction that letter writing will not go the way of the dodo.'
Festival organisers made it clear Mrs Maxwell would not be answering questions on her personal life and she did not once refer to her late husband. Instead, she told the audience how she continued to write hundreds of letters a year to her family and friends.
One male member of the audience snored occasionally as she threw in figures on how 2,323 million letters were written in 1900 compared to only 675 million in 1984, by which time the population had doubled.
As a child Mrs Maxwell had been intrigued by a treasure trove of unpublished 18th and 19th-century letters inherited by her family. After taking a degree in modern languages at Oxford she completed her doctorate with a thesis on letter writing.
She took exception to the critic who dismissed the private letter as 'a sewage farm of literature'. But she brought laughter from her audience when she spoke about an 18th-century French woman who sent a letter to her husband saying: 'I write to you because I have nothing to do. I end because I have nothing to say.'
Among the audience was her son Ian, who revealed that as a schoolboy he had received one letter a fortnight from his mother.Reuse content