This nocturnal clock -horologium nocturnale- is an astronomical instrument used to measure time by observing the Pole Star and the position of other bright stars. 

This nocturlab is a reproduction of the one built in 1568 by Girolamo della Volpaia(now in the Galileo Museum in Florence, former Museum of the History of Science). Because it was made before the Gregorian Reform (1582) and because of the inaccurate tables of the builder himself, to use it correctly it is necessary to add 38 days to the date of observation. (H 24).

Measurements:

Maximum Height: 16,5cm / Diameter: 14cm / Thickness: 3mm