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

405 of smoke; when the disc is half eclipsed, the colour is black; when more than half is eclipsed, the colour would be a blend of black and red and when the entire disc is eclipsed, the colour will be what is called pisanga or reddish-brown. Comm. Clear. Verse 37. When declare the occurrence of an eclipse. When even one-sixteenth of the diameter of the Moon's disc is shadowed, the eclipse will not be visible in as much as the shadowed portion is covered by the illaminating rays of the disc. In the case of the Sun, when even one-twelfth of the diameter is shadowed, the eclipse will not be visible for the same reason. Hence we shall not declare the occurence of an eclipse upto the shadowing of the discs to the extents stated above. Verses 38 and 39. Examples which disclose the invalidity of construing Valana in terms of Hversine instead of Hsine. When the Sun is in the zenith, the Ecliptic being vertical, the Valana is clearly seen to be the Agra of (☉+90) where ☉ is the longitude of the Sun. If you could show that the Valana will be the same on the basis of Hversine-formula, then I would accept that what Lallāchārya postulated in his work Śiṣya-Dhī-Vṛddhida is correct. Again, in a place of latitude 90—ω, ω being the obli- quity of the Ecliptic (ω is taken to be 24°), when the Sun being situated in Meṣa, Vṛṣabha, Mīna or Kumbha, the Moon contacts him from the south at the moment of a solar eclipse, in as much as the Ecliptic coincides with the horizon. In this circumstance, how could the Valana be equal to R, as made out by the Hversine-formula.