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

186 PAÑCASIDDHĀNTIKĀ VIII.8
(b) for the night-time work, find from the intervals the equation of the centre for the 784'
following, in the anomaly, and apply it to 790' as that itself would be applied.
Example 3. The days from epoch is 59, (given in the previous two examples). Find the Sun's and the Moon's
true daily motion, for the day gone and the day to come.
(i) In example 1, the last interval used is -33' 55". The 15th part of this is -2' 16". Applying
this to 59' 8", the Sun's true daily motion for both days is 59' 8" - 2' 16" = 57' (in full minutes).
(ii) In example 2, the Moon's mean anomaly used is rā. 4-4-46.
(a) For the day previous, the last 784' of this begins from rā. 3-21-42. The equation of the centre
pertaining to this part of the anomaly = + 30' × 8° 18' ÷ 15° + 47' 45" × 4° 46' ÷ 15° = + 16' 36"

• 15' 10" = + 31' 46", (say + 32'). Applying to the mean motion, 790', the true motion for the pre-
  vious day = 790 + 32 = 822'.
  (b) For the next day, we have to find the equation of the centre for anomaly from rā. 4-4-46
  to rā. 4-17-50. This is equal to, + 47' 45" × 10° 14' ÷ 15° + 1° 1' 51" × 2° 50' ÷ 15° = + 32' 35"
• 11' 41" = + 44' 16". Applying to the mean motion, the daily motion for the day following = 791'
• 44" = 835'.
  The instruction is easy to understand, for, clearly the difference in the longitudes of two consecutive
  days is the motion for the day. As, in the Romaka, the day begins at sunset for which the longitude
  is computed, the day-time before sunset falls in the day previous, and the night following sunset
  falls in the day next. Hence for work in each, respectively, the motion for the previous day and the
  next day has to be taken. To avoid computing the longitudes of both days, we have given an easy
  method, which should have been intended by the author also, for, otherwise, he need not have
  given the mean motions of the Moon and its anomaly.
  [राहुः]
  'त्र्यष्टक'गुणिते दद्याद् 'रसर्तुयमषट्कपञ्चकान्' राहोः ।
  'भवरूपाग्न्यष्टि'हृते क्रमात् झषान्तो (च्यु)ते वक्त्रम् ॥ ८ ॥
  Rāhu

8. Multiply the days from epoch by 24, add 56, 266 and divide by 1,63,111.
   Subtract the revolutions etc. obtained, from the end of Pisces, (i.e. from any
   whole number of revolution). The Head of Rāhu is obtained.
   The following is instructed to be done:
   (i) Revolutions etc = (days × 24 + 56,266) ÷ 1,63,111
   (ii) Head of Rāhu = rā. 12-0-0 - Revolutions etc, omitting the full revolutions.
   8a. B. त्र्यष्टगुणिते d. A. क्रमाझखांतोव्यते; B. क्रमादुखान्तोच्चते
   b. A. नाहो: (B2. क्रमातु दु०) ; C. क्रमात् झषान्तोत्क्रमात् वक्रमू
   c. A1. रूपानन्यष्ठि D. क्रमात् झषात् सोच्यते