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

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it will be seen that at the points O₁ and O₂ where O₁ is the
other geocentric pole of the circle (c) drawn there cannot
be an eclipse, the latitude being increased (as per Hindu
astronomy) by 48' – 46''. In fact, there will be eclipse
for the places on either side of O'' (the point of intersection
of the join of the centres of the Sun and Moon with the
Earth's surface) to such a distance as will increase the
latitude to 32' only. For the other places on O' O'' beyond
these points, the latitude of the Moon exceeds this limit
and so there will be no eclipse. Further clarification of
Lambana and Nati will be given later.
The above analysis underlies our investigation for the
occurence of a solar eclipse. Sapātasūrya might be less
than 7°, but it does not mean that every place will enjoy
an eclipse. So, for the place concerned, we have to see
that, even after taking into account the parallax in
latitude ie. in Nati, still the latitude will be less than 32'.
To obtain this parallax in latitude, the method adopted is
to find it at the point called Vithribha, (nonagesimal)
ie. the point which is behind the Lagna the rising
point of the Ecliptic by 90°; for, as we shall see in the
Chapter on Solar eclipses, the parallax in latitude at the
Vitribha will be equal to the parallax in latitude at any
point of the ecliptic. In other words, wherever be the Sun
and Moon on the ecliptic (Moon also being very near the
node may be taken roughly to lie on the ecliptic) to
compute the amount by which the latitude is increased, we
compute it for the Vitribha, and this will hold good for
the arbitrary position of the Moon, for, there also the
latitude will be increased by the same amount. The
procedure given in verse 4 is to locate the Vitribha from
the position of the Sun and to find its zenith-distance to
compute the Nati; or rather, it is to locate the culminating
point and taking it roughly to be Vitribha, to compute
the influence of Nati on the latitude or Śara. If it were
only to find the Vitribha, it could be computed from the