Lot 36: A NORTH AFRICAN BRASS ASTROLABE QUADRANT, 18TH - 19TH CENTURY

This Islamic scientific instrument is a brass astrolabic quadrant of traditional quarter-circle form. The instrument is constructed from a copper alloy and features hand-engraving on both faces. One face is engraved with an astrolabic projection for a specific latitude, including almucantar and azimuth lines, accompanied by inscriptions in Arabic or Ottoman Turkish script. The reverse face contains a universal sine/cosine grid, known as a rub al-mujayyab, utilized for trigonometric calculations and timekeeping. A decorative kursi or handle is attached at the apex, featuring pierced foliate openwork. This handle terminates in a hinged shackle and a lobed suspension ring. Two fixed sighting vanes are mounted along one radial edge of the frame.

L: 25cm