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

100 has stated. Bhāskara's statement yet has another mean- ing. The ecliptic from 180° to 360 being in the reverse as can be seen in fig. 27, the time by which a particular Rāsi rises, is equal to the time by which its seventh Rāsi or diametrically opposite Rāsi sets. It is important to note that the rising time of a particular Rāsi is not equal to its setting time as can be gauged from the rising times, for, then the rising times of Meṣa and Tulā must be equal which is not the case. The word विलोमसंस्थाः has this meaning as well, rising and setting being reverse directions. Incidentally there is what is called a वृद्धकारिका handed down i.e. a traditional statement which men- tions "मीनमेषौ चतुर्नड्यः सार्धं चत्वारिगोघटौ etc." This clearly pertains to the local rising times of the Sāyana Rāsis at a place of latitude 17°-45' i.e. in between Rajamundry and Vizianagaram, as in this latitude the chara Segments in asus will be 230, 184, 73 which give rise to such rising times. We next find what are called Nirayana Swōdayas i.e. the rising times for the locality of the Nirayana Rāsis i.e. the Rāsis from the zero-point of the Hindu zodiac. We shall obtain these magnitudes for Rajahmundry whose latitude is 17°-2'. We shall however take it as 17°; also we shall take the Ayanāṁsas to be 21° at present following Varāhamihira. This is one of the contexts where the knowledge of Ayanāṁsas is essential. The method is the same as followed before; only, we have to find the decli- nations, right ascensions, charas and therefrom the rising times of arcs of magnitude 21°, 51°, 81°......351°. Sub- tracting the preceding rising times from the following we have successively the required rising times. We shall give them under the following table.