Abraham van Diepenbeeck, Man with telescope observing seated male figure in an interior. Flemish, in or before 1631. FM: PD.63-1964 © Fitzwilliam Museum, University of Cambridge.

This entertaining sketch was produced to illustrate a moralizing emblem book, Anton van Bourgoinge’s Ghebreken der Tonghe (1631), which was printed almost simultaneously in two versions, one in Latin, one in Dutch. In this sketch by Abraham van Diepenbeeck, the telescope is being used not to look out into the mysteries of the cosmos, but to look in on an interior scene of a man at a table in a room furnished with his possessions. The text which it illustrates concerns the dangers that threaten your household when you are away from home. ‘Look, a thieving eye sneaks into your property’, a line in the Latin version of the printed book warns, directing the reader to turn their own eye on the scene of observation playing out in the image. At only 10 x 7cm, the book itself would slip easily into a pocket or purse, making it convenient to carry around as you made your way through the public spaces of Renaissance life.