A History of the Kerala School of Hindu Astronomy (in Perspective) c10.s6.31

c10.s6.31

Nīlakaṇṭha was a versatile scholar, though his writings, which are prolific and erudite, are all on astronomy. His *Tantrasaṅgraha* (A.D. 1500)¹ is a comprehensive treatise on astronomy. His *Grahaṇanirṇaya* and *Candracchāyāgaṇita*, the latter with his own commentary, deal with revised procedures on the respective topics. In his *Golasāra*² he gives a résumé of some of his views on certain astronomical topics and in his *Siddhāntadarpaṇa*,³ he sets out the astronomical constants, as determined by him, the rationale of which he expounds in his commentary on that work. In some elaborate tracts on eclipses and certain other topics (*Grahaṇādigrantha*) he expounds the tradition and rationale of eclipse computation, methods for determining corrections (*saṃskāra-s*) etc. His *Sundararājapraśnottara* forms his answers to certain astronomical problems posed by a contemporary astronomer from the adjoining Tamil region who has commented on the *Vākyakaraṇa* ascribed to Vararuci.⁴ Nīlakaṇṭha sets out much original contribution through his extensive *Bhāṣya* on the *Āryabhaṭīya*⁵ which is considered to be his masterpiece. But, by far the most instructive work of Nīlakaṇṭha is the *Grahaparīkṣākrama*,⁶ where, in about 200 verses, he sets out the procedures for the observation of the planets, sometimes with instruments, and for their computation using the data obtained from the observations. A commentary in Malayalam expounding the said procedures is also known.¹