This piece is a reproduction of an instrument dated 1570, signed by Humphrey Cole. This instrument is in the British Museum, London. The original piece has two faces, one of them being this Nocturnal Clock.
Horologium noctis is the Latin name of this nocturnal clock, an artefact used to obtain the time at night using the fixed stars in the sky. This instrument appeared at the beginning of the 16th century and went into decline in the 18th century. This piece is built to measure the time with the North Star and the star Kochab.