Astrolabe from the 16th century (Galileo Musuem - Florence)
The mariner's astrolabe was a simplified version of an instrument originally developed by Arab astronomers for measuring the height of heavenly bodies above the horizon and came into use in navigation by about 1470. In order to keep it steady when used on board a ship, the mariner's version was heavier and had parts of the disc cut away to reduce wind resistance.
(from an earlier visit)
Astrolabe from the 16th century (Galileo Musuem - Florence)
The mariner's astrolabe was a simplified version of an instrument originally developed by Arab astronomers for measuring the height of heavenly bodies above the horizon and came into use in navigation by about 1470. In order to keep it steady when used on board a ship, the mariner's version was heavier and had parts of the disc cut away to reduce wind resistance.
(from an earlier visit)