Jyotihshastra: Astral and Mathematical Literature c4.s6.7

c4.s6.7

The first text to describe the construction and use of the yantrarāja or astrolabe in Sanskrit was the Yantrarāja²⁷⁶ composed by Mahendra Sūri,²⁷⁷ a Jaina from Bhṛgupura, for Fīrūz Shāh in 1370. A commentary was composed by Mahendra’s pupil, Malayendu Sūri,²⁷⁸ in about 1382, and another, the Vilāsavatī, by Gopirāja²⁷⁹ in 1540. Mahendra has taken from an unidentified Arabic source not only the rules relating directly to the construction and use of the astrolabe (including a Ptolemaic star-catalogue adjusted for precession), but also a Sine table in which R = 3600 or 1, 0, 0 sexagesimally; a declination table in which ε = 23;35°; a list of cities (including a number in Islamic lands outside of India) with their latitudes expressed in degrees; and shadow tables for twelve and seven digit gnomons.