This work by Galileo (1564-1642) [The operations of the geometric and military compass] was published in Padua in 1606 and dedicated to Prince Cosimo de' Medici. It illustrates, with many figures, the operations that can be performed with the Galilean compass alone or in combination with the quadrant. The booklet was probably sold or given with a copy of the instrument. This explains why it contains no images of the instrument itself: these first appeared in the Latin translation (Galilaei de Galileis [...] de proportionum instrumento [...], Strasbourg, 1612), edited by Matthias Bernegger (1582-1640).