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No. 15.]
THE BRAHMA-SIDDHANTA: MEAN SYSTEM.
213
2.g. Required the tithi-index at mean sunrise of the day called "Abhädha fulla 4" in Saka 547 expired, or A.D. 625-26, and the corresponding A.D. day and week-day.
In this year there was no intercalated month. The interval from the day "Chaitra sukla 1" to the day "Ashādha sukla 4" is approximately (Table LXIII-A above, p. 335) 93 days. We try this
d. w.-d. a. Table xc. Chaitra sukla 1, mean sunrise , . (74) (6) 1846506 *Table LIVA for 93 days . . . . . +(93) (2) 1492.7746
(167)
(1)
1677-4252
This value of "a" (Table LXVIII) shews
that the 6th fukla tithi was current at mean sunrise. .Deduct for 2 days . . .
-(2)
-(2)
-677-2640
At mean sunrise on Ashādha fukla 4 . . . (165) (6) 1000-1612 Table LXVIII or VIII Indian Calendar, shews the currency of the 4th fukla tithi, at that mean sunrise, since its first point is when a=1,000. Day 165 was (Table IX, Indian Calendar, or LXIX, above) 14th June A.D. 625. 6=Friday. We learn, however, that the 4th mean tithi had begun only about of a minute before the moment of mean sunrise ; BO that if the basis of calculation had been the moment of true sunrise (a little earlier than mean sunrise) the corresponding day might have been Thursday, 13 June.
Erample 5. To find the nakshatra, or place in the heavens of the mean moon, at mean wunrise of any day or of any later moment in the day.
Take the case in the last example. It is required to find the value of " ". the nakshatraindex, at mean sunrise of the day called, in the mean system, "Ashädha fukla 4" in the given year, A.D. 625.
The mean tithi-index, "a", at that mean sunrise was found to be 1000 1612. Since s+a=n (8 327 above), we have to ascertain the value of "8", the sun's mean longitude at that moment.
The day, 14 June, was the 165th day after Jan. 1 in that year. Mean Mēsba-sankranti had taken place on (Table XC, cols. 13-17) the 79th day at 22h 30m 54' after mean sunrise. The day 14 June was (165-79) 86 days later. We proceed as follows:
2354-4957
Table LXXX, p. 444. Interval of 86 days Less (Table LXXXI) for 22h.
. .
.
. .
. .
25.0964 0-5704 0-0171
25-6839
-25-6839
At mean sunrise on the day Ashadha bukla 4 sun's mean long., "," = Ada "a" as already found for that moment . . . . .
2328-8118 1000-1612
At mean sunrise on that day "9"= . . . . . . 3328-9730 This last is the required nakshatra-index. Reference to Table VIII, Indian Calendar, or Table LXVIII (above Yol, XVI) shews that the moon was then in the nakshatra Aglésha by the
