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TRUE LONGITUDE OF THE SUN IN HINDU ASTRONOMY.
that the result of calculation from that amount of mean anomaly gives the sun's true longitude as exactly 360" down to four decimals of a second. The figures, then, are accurate for the moment of true Mesha-samkranti in K. Y. 4500.
The sun's mean longitude at any moment is his true longitude less the equation of the centre, here 360°-2° 8' 56"-040541156 or 357° 51' 3"-959458844, or, in 10,000ths, 9940-308329 158. These figures are given for the moment of true Mesha-samkrānti at the head of the main Table.
Bxample.
265. An inscription is found dated "Śaka 1571 Virōdhin, 15 krishna of Margasira, Sunday, (nakshatra) Parva-Ashaḍha, 24 Dhanus."
We work first by the Tables of the Indian Calendar in order to obtain a close approximation according to the Arya-Siddhanta.
The year was K. Y. 4750 expired, or A.D. 1649-50. Its samvatsara-name was Virödhin. In that year the lunar month Ashadha was intercalated.
Calculation for the lanar tithi proceeds as usual
(Beginning of lunar year) (Table IV. Intervening days)
(Egn. b, Table VI)
(Egn. c, Table VII)
(cx 10) (Constant)
(Less egn. c)
d.
63
294
...
357
w-d.
1
0
1
a. 29 9558
9587
211
54
245
b. C.
415 212 670 805
(Tithi-index) t=9852
The day, 357, was (Table IX) 23 Dec. 1649 A.D. The week-day was 1 Sunday. The value of t shews that at mean sunrise of that day the tithi was 15 krishna (Table VIII).
For the nakshatra, as by the rough rule
85 17
170 7207
7377
-54
(Sun's true longitude) (Tithi-index (above))
8,=
73231 t,= +9852 ... n,=
(Nakhatra-indos)
7175
This nakshatra-index shews (Table VIII) that by the equal-space system of nakshatras the moon stood, at mean sunrise of the day in question, in Pärva-Ashaḍhā.
1 Calculation by Tables XLVIIIA and B shews that this value of a at mean sunrise of the Sunday in question is correct according to the Arya-Siddhanta, the actual value being 7822-8775. By the Sürya-Siddhanta
it was 7820-7094
