'I am not amused, merely—interested. I have not before met a lady so determined to boast of her unmarried state and the fact that she understands more than the - er - the rudiments of mathematics.'

He was mocking her. 'Well, now you have!' Indignation and anger made Cressie indiscreet. 'And I do understand considerably more than the rudiments, if you must know. In fact, I have published a number of articles on the subject, and even reviewed Mr Lardner's book, Analytical Treatise on Plane and Spherical Trigonometry. I have also written a children's geometry primer which a most respected publisher has shown an interest in printing, and I am currently writing a thesis on the mathematics of art."

'If you are studying the relationship of mathematics to art, you must have read the definitive work by my fellow Italian. I refer to Pacioli, his De Divina Proportione?'

Pleased to discover that he was not the type of man to assume her sex prevented her from understanding such an erudite work, Cressie was at the same time distracted by how lovely the title of the book sounded when spoken by a native Italian. 'You have read it?' she asked foolishly, for he obviously had.

'It is a standard text. You agree with what he says, that beauty can be described in the rules of symmetry?'

'And proportion. These are surely the basic rules of any art?'

Signor di Matteo began to prowl restlessly about the room, frowning. 'If painting was simply about getting angles and proportions right, then anyone could be an artist'