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

436 (vide fig. 100) where M is the centre of the Moon and MD the latitude of the Moon at the point of first contact MD = MB + BD = m + BÊD where m is the semi- diameter of the Moon's disc. But BÊD = BEA + AÊS = CB̂E − CÂE + AÊS = P − p + s where P and p are the parallaxes of the Moon and the Sun and s the angular semi-diameter of the Sun. Thus in order that a solar eclipse may be possible for some point of the Earth, the latitude of the Moon at the moment of conjunction must be less than P + s + m − p = 57' + 16' + 15' = 89' approximately. The lesser the northern latitude of the Moon at the moment of conjun- ction, more places situated on the surface of the Earth between C and F will have solar eclipse where F is the sub-solar point ie. the point of the Earth which has the Sun in the zenith at the time of conjunction. Similarly, if the southern latitude of the Moon is less than 89' at the moment of conjunction the places situated on the Earth between G and F will have solar eclipse. In particular the sub-solar point F will have solar eclipse if the latitude of the Moon at the moment of conjunction is less than HD ie. less than s+m ie. 33' approximately. The sub- solar point will have no parallax, so that the terms P and p in P+s+m−p vanish. For the other points ie. points between F and C or G parallax will be there and the latitude may be greater than s + m but less than s+m+P−p to have an eclipse. A latitude of 33' corres- ponds to a distance of (33 × 15) / 70 = 99 / 14 = 7 1°/14 of the Sun with respect to a node. Thus if at the moment of conjun- ction, the latitude of the Moon be less than 7°, even the sub-solar point must have an eclipse. Verses 15, 16, 17. To find Spars'akāla, Mokṣakāla, Sammīlanakāla and Unmīlanakāla.