Astrolabes are the most admired and coveted of scientific instruments, but are also among the least understood. They are elaborate calculators, which were used by astronomers, navigators and astrologers to capture the movement of sun and stars, to determine local time, latitude, for surveying and to cast horoscopes. They are complex and challenging as well as mysterious, elegant and distant.
This astrolabe was made by Thomas Gemini for Queen Elizabeth I, and was probably a gift from her favourite Sir Robert Dudley. That such an object should be considered an acceptable gift to a monarch shows the significance of Astrolabes to astronomical and navigational observation in the 16th century, as well as the intelligence and education of the Queen.