Gunner's level made by Josua Habermel. The curved base was set on the breech end of the barrel to measure the gun's elevation. On the level slides a plate carrying a magnetic compass, a graduated circle with an index, and a vertical graduated rod with a cursor index. The center of the graduated rod holds a laterally mounted clinometer. Brought to Florence from Germany by Prince Mattias de' Medici in the first half of the seventeenth century.