ltwilliammowett: A Nocturnal made of Boxwood, maybe english, mid 16th centuryThis navigation tool,
ltwilliammowett: A Nocturnal made of Boxwood, maybe english, mid 16th century This navigation tool, known as a nocturnal, was used to calculate time at night. Similar to an astrolabe or a sundial clock. A pointer, much like a hand on a clock, determines the time at night based on the position of the North Star in relation to another constellation, such as Ursa Minor (the Little Dipper). -- source link