Nilakantha's Annual Astrology

Remaining Duration original: "bhogya-ghati" 10 pala 41; total Remaining Duration 64 pala 54. The elapsed time measured in ghatis, where 1 ghati is 24 minutes is 50 ghati 8 pala. From the first mansion, Ashwini, up to Purva Bhadrapada, 25 Nakshatras lunar mansions have elapsed. Multiplying this figure by 60 gives 1500. Adding the elapsed time of the current mansion, Uttara Bhadrapada (50;8), we get 1550;8. Doubling this results in 3100;16. Dividing by nine, the quotient is 344 degrees original: "ansha" with a remainder of 4. Multiplying the remainder by sixty and adding the remaining 16 gives 256. Dividing by nine gives 28 minutes original: "kala" with a remainder of 4. Again multiplying by sixty gives 240; dividing by nine gives 26 seconds original: "vikala". The calculated longitude of the Moon original: "ansha-adi-chandra spashta" is 344° 28' 26". Since the degree value exceeds thirty, we divide by 30; the quotient is 11 signs original: "rashi" with a remainder of 14. Thus, 11s 14° 28' 26" is the precise longitude of the Moon.

Another example is as follows: from Ashwini to the third quarter of Purva Bhadrapada, eleven signs have been fully traversed. With the fourth quarter of Purva Bhadrapada and 45 ghatis of Uttara Bhadrapada elapsed, three quarters are completed, meaning 13 degrees and 20 minutes have been traversed. That is, up to the 45th ghati of Uttara Bhadrapada, the Moon's longitude was 11s 13° 20' 0". Now, for the remaining 5 ghatis and 8 palas of Uttara Bhadrapada, the rule of three original: "trairashika"; a mathematical proportion is applied: if 15 ghatis correspond to 320 minutes of arc, how much corresponds to 5 ghatis 8 palas?

Multiplying the sum original: "pinda" of 5;8 ghatis (which is 308 palas) by the value 320 (represented here as 200) results in 61600. Dividing this by the total palas in 15 ghatis (900), the quotient is 68 minutes. Multiplying the remainder of 400 by sixty gives 24000; dividing by the divisor 900 gives 26 seconds. Since the minutes exceed 60, we divide by sixty; the quotient is 1 degree and the remainder is 8 minutes. Adding this result of 1° 8' 26" to the previously obtained 11s 13° 20' 0" gives 11s 14° 28' 26". Both methods yield the same precise result.

The second example was written above. (Now, the method for determining the Moon's velocity.) The span of one Nakshatra is 13 degrees and 20 minutes. Converting this to minutes gives 800; multiplying by sixty gives 48000 seconds. Dividing this by the total duration of the Nakshatra...