Lot 169: A PERSIAN GEM-SET BRASS PLANISPHERIC ASTROLABE, 19TH CENTURY

The instrument is constructed from cast and engraved brass and comprises a mater with an integral throne, a rete, a set of removable plates, a central pin, and a wedge in the form of a stylised horse. The throne, known as the kursi, features scrolling foliate openwork and is set with red and blue cabochon stones. The rete includes foliate star pointers and is engraved with Arabic star names and zodiacal information along its rings. The limb of the mater is graduated with degree scales and divided into hours using Abjad notation. The back of the instrument, or dorsum, is engraved with a shadow square at the base, a sine and cosine grid in the upper quadrants, and various circular scales for trigonometric and calendrical calculations.

L: 26cm