Going off piste. I like stories that infiltrate or mimic other forms: letters, recipes, inventories, instruction manuals. Here is a found story, both exact and mysterious in its dependence on another way of interpreting the world, in the form of instructions for calculating how much wine your barrel can hold. I like the deadpan tension between the absurd precision of the fractions and the deceptively random nature of the sequential instructions. I like the fact that the author is also the painter of The Nativity and The Baptism of Christ in London’s National Gallery: sublime brushwork and mathematical competence were not entirely separate skills, and Piero could assume the same mathematical knowledge from his lay-educated literate audience. And because I conceive of maths as a (very beautiful) language unto itself, reading this passage is like reading a story in translation. A braccio is an obsolete Italian unit of measurement based on the length of the human arm.

Published in Trattato d’abaco, c.1460; quoted in English translation in Michael Baxandall, Painting and Experience in Fifteenth-Century Italy, Oxford University Press, 1972