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No. 10.]
THE SIDDHANTA-SIROMANI.
161
pointed out, the only evidence available asserts that he used a radius of 3270. No complete copy containing the list of sines bas as yet been found, and it is & question whether the Bepares: printed edition can be relied on. Only one complete copy of the Räjamrigātika has come to light. This is in the Deccan College Library at Poona, which also possesses a fragment consisting of two chapters. Professor N. K. Majumdar of the Calcutta University, who has kindly made enquiries for me, writes that, although there seems to be frequent reference to a table of sines, such a Table is not to be found in either of the copies. It seems therefore somewhat premature to assert that Tables adapted for computation by the Siddhanta-Siromani will apply in all respects to work by the Rajanrigārika.
272. According to the Siddhānta-Siromani the length of the mean solar sidereal year, on the basis of 1,577,916,450 civil days to A yuga of 4,320,000 years, is 865-2584375 days or 3654 6h 12m , a quantity less than that of the Arya-Siddhanta by 21.
The sines of the 24 base angles of anomaly have the same value ns in the Arya- and SuryaSiddhāntas, with sin. 90°, or radius, = 3438. [See Table XLVII (above, Vol. XIV) for these sines and equations of sun's oentre. For the moon Bee Table LIX below.]
The epicycles of sun and moon are not contracted at any point. That of the sun has a circumference of 13° 40'; that of the moon 31° 36' (Jacobi, above, Vol. I, p. 441). The sun and moon are always treated as planets.
The line of apsides of the sun's orbit has a constant slight forward shift, the movement amounting to 00174 or 1*044 per annum. In the total period of 650 years embraced by my Table LX this shift amonnts to 11' 18"6.
The epoch of the Kaliyuga was the moment of mean sunrise, or 6 A.M. Lankā time, on Friday 18 Feb. B.C. 3102, a moment which for purposes of computation is treated as K. Y. O expired, Oh Om 0". This was the moment of occurrence of monn Mosha-bankranti in that year, when mean moon, mean sun and mean Jupiter were all considered to be in exact conjunction as the 0° point of celestial longitude. True Mēsha-sankranti in that year, i.e. the moment when the true sun touched that point, occurred on Tuesday, 15 Feb.at 19h 52m 217 after mean sunrise.
We have given the term “ fõdhya" to the interval in time between true and mean Meshagamkranti. In K. Y. O expired this was 24 4h 7m 38*50, or 2.171971 (Indian Chronography, Table, p. 16; Dr. Schram's valuation).
The position of the moon's apsis at K. Y. O was 305° 29' 46". Mean moon being at 09, her mean anom. at that moment was (360° -305° 29' 46'=) 54° 30' 14" (Jacobi, above, I, 442).
The position of the sun's apsis, perigee-point, at that moment was 257° 45' 36', and his mean anom. was (360° -- 257° 45' 36'=) 102° 14' 24" (Jacobi, above, I, 442).
EFFECTS OF THESE ELEMENTS. 273. i) Length of the mean solar year. Since, as above stated, the Siddhanta-Siromani year is less by 21* than the Arya-Siddhanta year, and since this divergence is annual and began in B.C. 3102 at the epoch of the Kaliyuga, when the two were together, it had, by the year A.D. 1100 when my Table LX begins, increased to more than 24 hours. Hence the moments of both mean and true Měsha-sankranti according to the Siddhānta-Siromani are always a day earlier than they are by the Arya-Siddhānta, the times of the occurrence of which are given in Table I of the Indian Calendar. To avoid constant reference to another volume, the Table of difference already published in Indian Ohronography, p. 61, is here reproduced. The moment of trae Mēsha-saņkrānti each year can be calculated from this, as explained in the work quoted; but all details are given in Table LX below.
1 Above, Vol. XIV, § 267.
