Replica of an antique astrolabe dated 1602	Replica of an Arabic Astrolabe from 1647

What is an Astrolabe?

Wikipedia gives this definition:
"An astrolabe (Greek: astrolabon, "star-taker") is a historical astronomical instrument used by astronomers, navigators, and astrologers. Its many uses include locating and predicting the positions of the Sun, Moon, planets, and stars, determining local time given local latitude and vice-versa, surveying, triangulation, and to cast horoscopes. It was used in Classical Antiquity, through the Islamic Golden Age, the European Middle Ages and Renaissance for all these purposes. In the Islamic world, it was also used to calculate the Qibla and to find the times for Salah, prayers." Qibla is the direction for a Muslim to face when praying.

In fact, astrolabes are beautiful works of art as well as being fascinating scientific instruments. At one time they could to be found in use across the civilsed world and were made from various different materials. The originals that survive today are very valuable and exist mainly in museums.

A Little History

The first astrolabe is believed to date from around 150 BC and was a combination of a sighting tube and a planisphere. Following its creation in the hellenistic world it continued to be used throughout the Bysantine period. The oldest surviving treatise in Greek on the astrolabe was written by John Philoponus, a Christian philosopher around 550 AD.

The Astrolabe was used widely throught the Muslim world and Arab mathematicians and astronomers contributed to its development. In particular, Al Sufi (also known as Azophi in the west), a Persian astronomer who lived in the 10th century, discovered many new uses and listed over a thousand in areas such as astronomy, astrology, horoscopes, navigation, surveying, timekeeping, Qibla and Salah prayer.

In the 14th century Geoffrey Chaucer, best known for his Canterbury Tales, wrote a treatise on the astrolabe for his 10 or 11-year old son. This was the first treatise in the English language on the astrolabe.

Abraham Zacuto perfected a metal astrolabe in the 15th century providing greater accuracy than previous models that were generally made of wood. Four identical 16th century astrolabes which still exist indicate that they were being mass produced at this time.

Antique Replicas

The potted history given above merely skates over the surface of the development and use of the astrolabe and is intended to wet the appetite of anyone with an enquiring mind. A wealth of additional information is available across the web which reveals many related nuggets of information. For example, did you know that the Large Magellanic Cloud can be seen from the Yemen and was identified by Al-Sufi six centuries before Magellan?

A study of the astrolabe can provide many hours of pleasure but would be incomplete without handling and learning to use the device itself. To make this possible we offer a range of antique replicas that provide a genuine feel for the way the instrument would have been used in practice.

Watch this video presentation on the Astrolabe - it gives a good introduction to this fascinating device.