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No. 14.]
THE FIRST ARYA-SIDDHANTA: "TRUE" SYSTEM.
109
A.D. 899, mean Měsha-sankranti having taken place on the previous day, Saturday, at 17h 20m after mean sunrise. Following general practice, I work for mean sunrise on the day on which the mean samkrānti occurred, i.e. for the Saturday, and deduct one day's values from the above.
Finally then the working values for the beginning of K. Y. 4000 (Sat., 24 Mar., A.D. 899, mean sunrise) are
a=2648.921808551 b= 486-863468853 c= 281-355996857
301. The century Table LXXII below is prepared from these details by addition of century increases. All the centuries concerned except century 42, which was defective, are common ones, each of 36526 days.
Table LXXIII gives the increases of a, b, c for each year of the century, following Lalla's bija.
Table LXXIV gives the values to be added for the days intervening between that on which true Mēsha-samkranti occurred in each year and the day of the corresponding beginning of the luni-solar year, i.e. the civil day called "Chaitra bukla 1." This Table is prepared for the purpose of assisting workers to check the main Table entries giving the values of a, b, c (Table LXI, cols. 23-25). The week-day stated in the main Table will always serve as a guide Compare the similar Table in my article on the Siddhanta-firomani (Vol. XV, pp. 159-245 abore) where instructions for its use are given ( 279),
THE NAKSHATRA.
302. A special note must be made regarding the working of the "Indian Calendar" rule ($ 156, p. 97) for obtaining approximately the index of the nakshatra.
It will be observed there that part of the process (see $ 133, Ind. Cal.) consists of the addition to the value of c, the sun's mean long., of a constant, viz. 7207, as stated in 10,000ths of circle. This is the Sürya-Siddhanta quantity. For work by the Arya-Siddhanta we require the Arya-Siddhānta quantity.
The Surya-Siddhanta figure is made up of (i) long of sun's perigee-point (257° 15' 55-7=) 71463 and (ii) 60-4, the greatest equation of the sun's centre.
Now (i) the long. of the sun's perigee-point according to the Arya-Siddhanta is always 2589, or, in 10,000ths of circle, 71666 ($ 290, v, above); and (ii) the greatest equation of the sun's centre (&$ 295, 296) is 59.6875. Hence the Arya-Siddhānta constant for calculating the nakshatra is (7166-6+59.6875=) 7226-3542; and for approximate calculation is 7226, not 7207.
There appear to be two misprints in Prof. Jacobi's Table VI (abour, Vol. XI, p. 166), in which he gives similar annual incremes. Against year 3, under *c," "81" should be "B", and against year 52, ander"," “16912" should be "16852."
