A curious world we live in,’ said Franklin Merton, ‘where one can afford a house but not a picture of a house. That must tell us some profound truth. But what, I wonder?’   The picture he was talking about was Simon Alpheton’s Marc and Harriet in Orcadia Place , later bought by Tate Britain – simply ‘the Tate’ in those days – and the house the one in the picture, Orcadia Cottage. His remark about the curious world was addressed to the Harriet of the picture, for whom he had bought it and whom he intended to marry when his divorce came through. Later on, when passion had cooled and they were husband and wife, ‘I didn’t want to get married,’ he said. ‘I married you because I’m a man of honour and you were my mistress. Some would say my views are out of date but I dispute that. The apparent change is only superficial. I reasoned that no one would want my leavings, so for your sake the decent thing was to make an honest woman of you.’   His first wife was Anthea. When he deserted her he was also obliged to desert their dog O’Hara and to him that was the most painful thing about it.   ‘You don’t keep a bitch and bark yourself,’ he said to Harriet when she protested at having to do all the housework.    ‘Pity I’m not an Irish setter,’ she said and had the satisfaction of seeing him wince.   They lived together for five years and