Using a Nocturnal

Using a nocturnal to find time at night by observing stars, from Peter Apian, Cosmographica Petri Apiani, 1574. 

Caption:
A nocturnal is used to find the local time at night by observation of stars near the North Pole.
Type: Illustration
Credit: National Museum of American History, Smithsonian Institution
Origin: National Museum of American History, Smithsonian Institution
Navigation Methods
 
A nocturnal is used to find the local time at night by observation of stars near the North Pole.