An Astrolabe is a projection of the celestial sphere onto a plane surface which was used in ancient times by astronomers and astrologers to find the position of bodies in the heavens. Astrolabes are quite complex and were often magnificent artistic masterpieces which took many years to produce. The Mariner's Astrolabe is a much simplified version used by navigators to measure elevation angles of the sun or stars in the rough conditions at sea.
The Navigators' Compendium is a collection of instruments for measuring solar time and elevation angles on voyages. It includes calibrated plates to help find your latitude, star charts with cut-outs to be aligned with the stars in both hemispheres, a quadrant and a mariner's astrolabe. This set was produced for a voyage which planned to re-create the 3 year return voyage of Marco Polo from China to Venice.
A Quadrant is a simple but very useful instrument which can be used for navigation, surveying and for telling the time,by measuring the elevation of the sun and stars. It is named from its shape, one quarter of a circle. The curved edge is divided from 0 degrees to 90 degrees and at the right angle vertex a cord is attached with a small lead or brass weight at the other end. A pair of metal pin-hole sights are mounted on one edge. By holding the quadrant vertically and aligning the sights on the sun or star, the angle of elevation can be read off the degree scale by the position of the cord which is kept vertical by the weight. This simple instrument was the forerunner of the sextant.
We produced this particular sun compass for 'Project Blizzard' where a group of young Australians sailed to Antarctica in 1984-1986 to survey and begin conservation of Mawson's Hut, the main base of the 1911-14 Australian Antarctic Expedition during the 'heroic age' of Antarctic exploration. 'Project Blizzard' also retraced part of Mawson's ill-fated traverse of the icecap, which is an epic Australian legend.
Proximity to the magnetic poles renders a magnetic compass useless. Nowadays satellite navigation and GPS (Global Positioning System) can be used, but a sun compass is a more realistic option when re-living the adventures of past eras.
A crew of 8 sailed this outrigger wooden boat across the Indian Ocean from Bali to Madagascar off the Eastern coast of Africa, basically following the current at about 13 degrees South latitude. The purpose of their trip was to verify that the native population of Madagascar originated from Bali 2500 years ago. The expedition was named 'Flight of Sarimanok' after a mythical bird, 'Sarimanok'.
The expedition used no modern navigation instruments. Sundials Australia made them an instrument which allowed the crew to determine True North in a way which the ancients may have done.
Reproduction sundials of any kind can be made to special order, as can replicas of ancient Navigation Instruments. We have designed and supplied solar navigation instruments for expeditions and re-enactment voyages of discovery on land and sea all around the world.
Expert repairs can be made to damaged sundials and instruments such as sun compasses, astrolabes, quadrants etc. Contact us to discuss your specific requirement.
A Sundial is used for finding the time at a given location, while a Sun Compass is used for finding direction when you already know the time.