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

SṚṄGONNATYADHIKĀRA
Verse 1. Either in the last quarter of a lunation, or
in the first quarter, on the day when the elevation of the
cusps of the crescent Moon is to be determined, then either
at the moment of Moon-rise or Moon-set or (for the matter
of that during any part of the night) the Hsine of the
altitude of the Moon is to be computed by noting the time
from the moment of Moon-rise.
Comm. Either in the first quarter or the last quarter
of the lunation, ie. when the phase of the Moon according
to the definition of phase in modern terms is less than
half, the Moon will be a crescent. Also, generally, on the
back-ground of the horizon, we notice that one of the
cusps is more elevated than the other. This elevation
goes by the name Sṛṅgonnati.
Even in the middle half of the lunation, Bhāskara
mentions that Brahmagupta and some others (meaning
Sripati whom he closely follows) attempted at finding the
elevation (strictly speaking elevation during the second
quarter and depression during the third quarter) of the
dark horns. Bhāskara does not appreciate this since,
nobody would think about this as it does not appeal to the
eye at all.
Verse 2. To find the Hsine of the altitude of the Sun.
The Hsine of the altitude of the Sun is to be
com-puted, assuming the rising Sun to be in the opposite
hemisphere, south or north (ie. if he be originally in the
northern, assume him to be in the south) and using the
formula given in verse 54 of Tripras'nādhyāya "अथोन्नता-
दूनयुताच्चरेण" given the time measured in asus that has
elapsed after Sunset.