Military instrument probably made by Joost Bürgi, as suggested by the initials I.B.F. [Iost Burgi Fecit]. Consists of a graduated central rod carrying a magnetic compass, a plumb bob, and a horizontal dial complete with gnomon. Along this rod slides a cursor, to which are hinged two graduated arms carrying two other small rods at the ends. As with item inv. 2510, this arrangement appears to be a variant of the radio latino, given the parallelogram shape formed by the jointed arms. The instrument was therefore used for measuring angles, heights, and distances and for surveying. Brought to Florence from Germany by Prince Mattias de' Medici in the first half of the seventeenth century.