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

226 | PAÑCASIDDHĀNTIKĀ | IX.27 It has already been mentioned that half the duration subtracted from the final parallax-corrected new moon is the beginning and added to it is the end of the eclipse. Further, if the difference of the semi-diameters is used in the work, instead of the sum, the duration of total eclipse is got. Here, if the Moon's is greater, there is actual total obscuration. If the Sun's is greater, there is annular eclipse. The author expects us to be conversant with these things. तिथ्यवना(मो) ग्रहणादिना(म)विश्लेषि[तो यु]तः स्थित्याम् । गोलाऽन्यत्वे देयस्त्ववनामो[मौ]क्षि(क)स्यैवम् ॥ २७ ॥ 27. Find the nāḍis of parallax for the time of the beginning. If the time of beginning and the new moon are both in the forenoon or both in the after- noon, find the difference of the nāḍis of parallax and add it to the half duration to get the correct half duration to be subtracted from the time of the corrected new moon. If one is before noon and the other afternoon, add the nāḍis of parallax, and add it to the half-duration to get the correct half-duration (to be subtracted from the time of parallax-corrected new moon). Do the same for the time of the end of the eclipse, (to find the correct half duration to be added to the parallax-corrected new moon, to get the correct last contact). The following example will make the meaning clear. Example 19. To continue Ex. 10. We have already obtained, par.c. new moon = nā. 23-20, parallax-correction for new moon = nā. 2-40, and the total duration nā. 5-1. Applying the half duration on both sides of p.c.n, the approx. time of first contact = nā. 20-50, last contact = nā. 25-51. The parallax correction in time for first contact using verses (22-23) is nā. 1-50. As both the new moon and time of first contact are in the same part of the day, i.e. afternoon, the difference between their parallax correction = nā. 2-40 − nā. 1-50 = nā. 0-50. This is to be added to the half duration to get the first half duration. Adding, nā. 2-30 + nā. 0-50 = nā. 3-20. Subtracting this from the parallax-corrected new moon, the correct time of first contact = nā. 23-20 − nā. 3-20 = nā. 20-0, after sunrise. Next, the parallax-correction for time of approx. last contact is nā. 3-30. As both new moon and last contact are in the afternoon, subtracting the corrections, for both from each other, we have nā. 3-30 − nā. 2-40 = nā. 0-50. Adding this to the half-duration we have, nā. 2-31 + nā. 0-50 = nā. 3-21, for the correct second half duration. Adding this to the p.c.n, the correct time of last contact = nā. 23-20 + nā. 3-21 = nā. 26-41 after sunrise. The following is the explanation of the rules for the correction given here and the justification for our interpretation. At first the duration is given neglecting the effect of parallax on the time. If the parallax is taken into account, the duration will always be longer than otherwise, as we have said. This can be seen from the following consideration. Let us take the case when the end of new moon 27a. A.B. नाम b. A.B.C.D. ॰दिना च वि॰. A.B. विश्लेषित; c. B. ॰न्य चेदेय C.D. विश्लेषितः d. A. स्त्वनामो A.B. Hapl. om of मौ