A History of the Kerala School of Hindu Astronomy (in Perspective) c9.s5.16

c9.s5.16

As indicated earlier, the composers of *karaṇa* texts generally started their works with contemporary epochs. Sometimes they also started with corrections to the astronomical constants, and to the sine tables which they incorporated in their works. A work mainly devoted to the enunciation of corrected constants is the *Siddhāntadarpaṇa* of Nīlakaṇṭha Somayājī, wherein he has set out the number of revolutions of the planets, and their higher apses, ascending nodes, maximum latitudes, velocities etc., as investigated and verified by him. He has also written an elaborate commentary on this work. Some short tracts call themselves *Khaṇḍavum dhruvavum* and merely give the epoch and the corresponding zero-corrections as determined by their respective astronomer-authors. Then again, there exist a large number of manuscripts which form collections of sine tables and mnemonics and are catalogued in libraries under generic titles like *Jyāḥ, Jyotiṣa-vākyāni* etc. on account of their not being full-fledged and independent works. These collections are potential sources of additions and novelties to the well-known mnemonics and, so, deserve to be examined from this point of view.