|About the astrolabe|
The home page of this site is dominated by the image of an astrolabe, and a detail of a three-dimensional version of the same instrument – the armillary sphere – is used as the icon in the location bar. Like horoscopic astrology itself, the astrolabe came into existence in the Hellenistic world in the 2nd century BCE, and throughout its history it has been used to cast horoscopes.
Like many aspects of astrological theory and practice, the astrolabe was developed and perfected in the Perso-Arabic world, where its Greek name – astrolabon, meaning ‘star-taker’ – became asṭurlāb, and astrological authors such as Māshā’allāh (c. 740–815) also wrote manuals on its use.
In late medieval times, the art of the astrolabe was part of the astronomical-astrological lore which passed into India, becoming known as the Tājika (‘Persian’) school. Jaina author Hemaprabha Sūri wrote in his Trailokyaprakāśa or Light on the Three Worlds (one of the earliest surviving Sanskrit works on Tājika):
In Tājika there are instruments, foremost of which is the sturlāva [asṭurlāb = astrolabe]. To those desiring to establish the ascendant, they accurately relate its six divisions.
A century later, Mahendra Sūri wrote a Sanskrit treatise on the astrolabe, which he called yantrarāja, ‘the king of instruments’. By this time the astrolabe had also reached the Latin-speaking west.
The astrolabe has followed astrology on its journey across countries and cultures, an invaluable practical tool and a symbol of accuracy and precision. It also brings to mind the mechanical clocks of which it is a forerunner, with the associated ideas of astrology as a study of the qualities and unfolding of time.