Small quadrant with case, attributed to the maker Josua Habermel. The limb carries a double graduation for measuring heights and distances. The front is engraved with two open compasses. The sights are fixed, while the index arm is mobile, with a steel spring serving as guide. On the back is a table for computing Easter and the inscription iuxta Kalendarii reformationem [after the calendar reform]. Brought to Florence from Germany by Prince Mattias de' Medici in the first half of the seventeenth century.