Sense of Direction

A three-dimensional studio seen from above and to one side: a sheet of white paper on a table, lit by the real sun over London at its real angle, with a fruit fly standing on the paper. The fly walks in bouts, and a brush under its body lays down a line in four watercolour pigments — Hansa yellow, quinacridone rose, ultramarine and phthalo green — mixed in the proportions its four colour-sensitive medulla cells are firing at. It walks in straight runs and turns at corners rather than curving; it stops, and where it stops the brush pools; and now and then it puts its wings out, flies across the sheet with the brush off the paper, and starts a new stroke where it lands. The drawing is whatever has accumulated since the piece opened. After dark a lamp on the table lights the studio and the fly keeps working under it. Nothing in the picture is decorative: the light, the fly’s heading, its gait and the colours are all outputs of the model, and the numbers they come from are listed below this image.