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

VIII. 11 VIII. ROMAKA-SIDDHĀNTA — SOLAR ECLIPSE 187 Example 4. Compute Rāhu for the moment, 59 days from epoch. (i) Revolution etc. = (59 × 24 + 56,266) ÷ 1,63,111 = rā. 0-4-7-19. (ii) Head of Rāhu = rā. 12-0-0 - rā. 4-7-19 - rā. 7-22-41. From this the tail = rā. 7-22-41 + rā. 6-0-0 = rā. 1-22-41. We have said that the Moon's node is called Rāhu, on account of the connection between the two. Of the two nodes, the first is the Head and the second, situated six signs away, is the Tail of Rāhu. According to the Romaka, there are 24 revolutions of the Moon's nodes in 1,63,111 days. There- fore, multiplying the days by 24 and dividing by 1,63,111 the revolutions are got. As the motion is retrograde, what is obtained has got to be treated as negative, and therefore to be subtracted from 12 signs or full revolutions. At the moment 56,266/24 days before Epoch, the Head of Rāhu was a full revolution, and in order to reckon from that time 56,266 is added to the days multiplied by 24. As for the correctness of the numbers, we cannot verify them since the original is lost. But we can see how nearly correct the Romaka Rāhu here given is, by comparison with that of other systems. At Epoch the Head or Rāhu according to the Romaka = rā. 12-0-0 - (0 × 24 + 56,266) ÷ 1,63,111 = rā. 7-25-49. Actually it is rā. 7-26-0. According to the Paulīśa it is rā. 7-25-59, and according to the Saura, rā. 7-26-6. The time for one tropical revolutions is 1,63,111 ÷ 24 = 6796-17-30 days. The correct time is 6798-21-48. The difference of 2-4-18 days is caused by the wrong constant of precession adopted by the Romaka, of 34" instead of the correct 50". Thus, since the Romaka precession is less by five minutes in the time taken by one revolution, its period of revolution must be about two days less as it is found to be, and the disagreement is small indeed. [लम्बनम्] दिनमध्यमसंप्राप्ता यावत्यो नाडिका व्यतीता वा | ताभ्यः षड्गुणिताभ्यो ज्यात्रिंशां'शस्थितेर्नार्म [:] || ९ || Parallax in longitude 9. (This is the same as VII. 1. and explained completely there. There is no difference in meaning between the readings there and here, dinamadhyama- samprāpyā and dinamadhyamasamprāptā). [दृक्क्षेपः] उदयात् प्रभृति च नाड्यो याः स्युः प्राग्लग्नमानयेत्ताभिः | तस्मात्तु नवसमेतादपक्रमांशान् विनिश्चत्य || १० || लग्नत्र्यगुविवरज्यां द्विगुणां स्व'रसां'शसंयुतामपमात् | जह्याद् दिग्द्व्यत्यासे विक्षेपैक्ये तयोर्योगः || ११ || 9. Quoted by Utpala on BS 5.18 c. B. षड्गुणिता योज्या 9a. B. मध्यसमं प्राप्ता d. A.B. तिथिर्नार्म; C. तिथेनार्म b. B. यायत्या. A. त्यो दिनाधिका 25