Mariner's astrolabe "Aveiro"

​​​​​​Mariner's astrolabe "Aveiro" 

Unknown manufacturer  
Origin: Portugal
Date: Circa 1575
Material: bronze  
Diameter: 197 mm.
MM.05255

Portuguese mariner’s astrolabe from the late sixteenth century, around 1575. It was found in Aveiro, in 1994. Its custody was granted to the Maritime Museum by the Secretary of State for Culture. It is in fair preservation conditions, as it still has the suspension ring and alidade. It has a scale used to measure zenithal distance, a common feature in Portuguese mariner’s astrolabes. ​