Lot 128: A PERSIAN BRASS PLANISPHERIC ASTROLABE, 19TH CENTURY

An antique planispheric astrolabe constructed from engraved and pierced brass. The instrument comprises a heavy outer case or mater with an integral throne featuring openwork foliate scrolls and a suspension ring. It contains five thin brass plates, or tympans, each engraved on both sides with stereographic projections including almucantars, azimuths, and hour lines for various latitudes. The plates are overlaid with a rete, a pierced circular framework representing a celestial map with stylised foliate star pointers and an ecliptic band. The entire assembly is intended to be secured by a central pin and a screw-top nut, which are present but currently detached. The limb of the mater is engraved with a numerical scale in the abjad system. The reverse of the mater is engraved with multiple astronomical and surveying scales, including a shadow square, a sine/cosine quadrant, and concentric calendrical and zodiacal circles. Extensive Arabic calligraphy identifies star names, latitudes, and directions such as al-Mashriq and al-Maghrib.

L: 23cm