पञ्चसिद्धान्तिका (आचार्य वराहमिहिर - सूर्य, रोमक, पौलिश, वासिष्ठ एवं पितामह सिद्धान्त)

VIII.7 VIII. ROMAKA-SIDDHĀNTA — SOLAR ECLIPSE 185

making the additive constant 622½. That is why in our rules for computation we have given this constant. Perhaps the author wanted to avoid the fraction in the constant. The anomaly computed for Epoch in revolution etc. = (0 × 110 + 622½) ÷ 3031 = rā. 9-12-16. Compare this with the actual, rā. 9-9-34, Saura's rā. 9-9-47, and Siddhānta Śiromaṇi's rā. 9-11-23.

The intervals of the equation of the centre are given in minutes and seconds as in the case of the Sun, with the special mention of degrees where there are full degrees. But the text here is so corrupt that we are not certain about the numbers, since the original Siddhānta is lost. So we have to depend much on guessing. Adding the intervals we understand that in this Siddhānta the Moon’s maximum equation of the centre is 4° 55' 48". Using this, and not doing the correction to the epicycle, since it is not known, we have computed the intervals and given them hereunder, for comparison with the given values:

Anomaly 15° 30° 45° 60° 75° 90° Computed Values 1° 16' 34" 1° 11' 20" 1° 1' 15" 47' 1" 29' 33" 10' 5" Given Values 1° 14' 25" 1° 11' 48" 1° 1' 51" 47' 45" 30' 0" 9' 59"

In the matter of order of taking the intervals and of adding or subtracting them our remarks under the sun hold here too.

[रवि-चन्द्र-भुक्तिः] 'खनवनगाः' शशिभुक्तिः ('कृ)तवसुमुनयः' शशाङ्ककेन्द्रस्य | यातस्फुटान्तरे दिवसभुक्तिरागामिकी नैशी || ७ ||

Daily motion of the Sun and the Moon 7. The daily motion of the mean Moon is 790', and that of the mean anomaly, 784'. For work relating to the day-time the true daily motion is the difference between the true Moons of the taken day and the previous day. For work relating to the night-time the true daily motion is the difference between the true Moon’s of the taken day and the next day.

The true daily motion, given in the second half, pertains both to the Sun and the Moon. The daily mean motions of the Moon and its anomaly alone is given because in the case of the Sun both are the same, practically, equal to 59' 8", and well known. It would have been better if the Moon’s mean daily motion had been given as 791'. Thus, the following is intended:

(i) To get the true daily motion of the Sun, take the last interval used in obtaining the true Sun, divide it by 15, and apply it to 59' 8" as the quantity got from the last interval has been applied to the mean Sun. This can be taken as true daily motion for both the day-time and the night-time as there is not much difference.

(ii) To get the true daily motion of the Moon: (a) for the day-time work, find from the intervals the equation of the centre for the last 784' of the anomaly, and apply it to 790' as the last part of the interval itself is applied.

7a. A1.B1.वनगा c. B.यातः स्फुटा; CD. याता स्फुटा b. A.क्रतव B.तत्तव०. B.शशङ्केन्द्रस्य d. A.B1.2.सभुक्ति आगामि