This Mariner’s Astrolabe was salvaged from the Dutch ship, Vergulde Draeck, which was wrecked off the west coast of Australia in 1659. It was adopted from the type used on land by the ancient Greeks and later the Indians, Persians and Arabs.
The mariner’s astrolabe was used to determine the latitude of a ship at sea by measuring the sun’s noon altitude or the meridian altitude of a star of known declination. The mariner’s astrolabe was a graduated circle with an alidade used to measure vertical angles. They are a version of the astrolabe proper and were designed to be use on boats in rough water and in heavy winds.
In order to use the astrolabe, the navigator would hold the instrument by the ring at the top. This caused the instrument to remain in a vertical plane. The navigator would then align the plane of the astrolabe to the direction of the object of interest. The alidade was aligned to point at the object and the altitude was read off the outer degree scale.
The Vergulde Draeck was a 42-metre, 260-tonne ‘Jacht’ constructed in 1653 by the Amsterdam Chamber of the Dutch East India Company or VOC. In 1656, the Vergulde Draeck struck a submerged coral reef of the Western Australian coast. The Vergulde Draeck was re-discovered in 1963.
- Title: Mariner’s Astrolabe from the Vergulde Draeck
- Built: 1600’s
- Findsite: Vergulde Draeck wreck
- Find Date: 1963
- Museum: WA Maritime Museum
“We are like islands in the sea, separate on the surface but connected in the deep.”
Photo Credit: By GordonMakryllos (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons 2) By Johannes van Keulen [Public domain], via Wikimedia Commons