11 on these circles, the geocentric position of the planets, declination and its measurement. The author also gives his views on the occurrence of the yatpat4-9, the extent of the lumar crescent and the data on which eclipses are to be calculated Appendices The two Appendices are later anonymous compilations, the purpose of which is to give, in the more popular k८८payadi notation of expressing numbers, the figures given according to the bl21a saikh ya system in the text. Besides this, Appendix I gives some further useful information, wi2., the actual position of the planets at the begin ming of the Kali era as calculated with the constants enunciated in the Siddhanta-darpura, the position of the higher apses and the ascending modes of the planets at the end of Kali 'year 4800 (A.D. 1697-98) and the geocentric positions of the planets at a definite date expressed by the chronogram arl21 1505iseyal (17,55,000) which works out to A.D. 1704. The last number is a constant or 'partial' (khara) intended to be subtracted from the number of Kali days of any later date on which the position of the planets is to be calculated. It would be natural to suppose from this that,Appendix I was composed after the The Commentary In 1ine with his Bhasya on the Aryabhaya, Nilakartha's commentary on the Srddhव71to-darp00 is elaborate and discursive Alongside explaining the text proper, it introduces related topics by way of background, illustration and rationalisation. Often, the commentary dilates into verse, a practice with Kerala astronomers like Parame5vara. This feature is found also in Nilakantha's Aryabharya-Bhasy८. Nilakaptha's discursions are often highly instructive. Aा instance in point is his detailed analysis of the mental working of a mathematician who proceeds to derive the relation between the sides and 1. See Parameswara's super-commentary Siddhantandpika included in the EdIn. of Mahabha७kary0 of Bhaskarācārya with commentaries , by T.S. Kuppamma Sastri, Madras, 1957, (4adras Govt. (07. Serie, No, 130)
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