सिद्धान्तशिरोमणि: गणिताध्याय (भास्कराचार्य - ग्रहगणित, मध्यमाधिकार व स्पष्टाधिकार सटीक)

387 = 222638750 / 1317628 = 169 approximately. Hence the increase of the Sun's longitude with respect to a node is 1 Rāśi + 2/3 (1 + 1/169)° I. In the beginning of the Kali- yuga, the longitude of the node was 5 Rāśis—3°—13′ and the arc moved by the Sun with respect to the node during the course of half a lunation is 0—15—20, so that their sum is 5 —18 —33. Here we have added for half a lunation because the context is a lunar eclipse and the beginning of the Kaliyuga was a New Moon day. Also, at the begin- ning of the Kali, the Mean Sun being at the zero-point of the zodiac, the negative longitude of the node only is the longitude of the Sun with respect to the node. Hence we have to add the above longitude of 5 —18 —33 to the longitude obtained through the above formulation I, which means 168°—33′ is to be added to 2x/3 (1 + 1/169) where x is the elapsed number of lunations. Taking 168°—33′ as nearly equal to 168°—40′, 2x/3 (1 + 1/169) + 168 2/3° = 2x/3 (1 + 1/169) + 506/3 = 2x/3 (1 + 1/169) + 503/3 (1 + 1/169) approximately = (2x + 503)/3 (1 + 1/169) as formulated. Thus for x lunations, the longitude of the Sun with respect to the node is x Rāśis + (2x + 503)/3 (1 + 1/169)°. If this longitude falls short of 14°, we could except a lunar eclipse. Latter half of verse 3 and verses 4, 5. Particularity with respect to a solar eclipse. Add half a Rāśi to the longitude previously obtained; find out on which side the Sun lies, north or south; com- pute the longitude of the Sun from the number of days 43