PLANISPHERIC ASTROLABE; North India; diam. 360 mm, weight 4. - Lot 185

PLANISPHERIC ASTROLABE; North India; diam. 360 mm, weight 4.580 kg; silver; Nâgarî (Sanskrit) script. Spider for 29 stars, 20 of which are named, with almost complete equatorial circle. This astrolabe consists of a single tympanum for latitude 27°. The limb is divided by 1/2 degrees and numbered in groups of 6º. The word "Sakti", i.e. power, is engraved on the front of the throne. On the back, degree scales, sine/cosine graph, shadow square (0-12-0 and 0-7-0), astrological chart and zodiac sign arcs with 9 hourly scales inscribed in ghâti. The alidade pinnae are fitted with a sighting tube and small sighting holes. Silver astrolabes are virtually unknown, although they are referred to in Islamic literature, such as: The Thousand and One Nights; this instrument was probably commissioned by a royal client. However, its interest lies not only in the value of the metal from which it is made, but also in the unusual presence of a ghâti scale that enabled the instrument to be used as a sundial, with the aid of the alidade (cf. unequal hours diagram on European astrolabes). Provenance: - Sale at Hôtel Drouot, room 8; Me E. Libert & A. Castor, Collection de Monsieur R - Instruments scientifiques anciens, April 28, 1982 - Private collection, preserved by descendants.