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

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ence of the earth pertaining to the locality. If d be this
distance then the rule of three to be used is “ If the
length of the rectified circumference viz. C rotates by the
time the planet moves a distance δm, what is the arc
traversed through by the planet if an arc ‘d’ of C rotates
through ? ’’ The answer is (d × δm) / C which is the cor-
rection required.
Verses 4, 5, 6. The Correction Desāntara expressed
in time.
The eclipse of the Moon occurs at a place situated on
the east of the primary meridian later than on the primary
meridian and vice versa. The time in between the two
moments is the Deśāntara expressed in time. The distance
of Desāntara ie. the distance of the locality from the pri-
mary meridian measured along a parallel to the terrestrial
equator or Niraksha Rekhā is obtained by multiplying the
rectified circumference by the Desāntara measured as above
in ghatis and dividing by 60. Also the above time in
ghatis multiplied by the planets’ daily motion and divided
by 60, gives the correction in arc in the computed mean
planetary motion.
Further the week-day begins after or before the local
Sun-rise by that Desāntara expressed in time according as
the locality is on the east or west of the primary meridian.
Also the week-day begins after or before the local Sunrise
by the ghatis of the correction known as chara according
as the Sun is in the northern or Southern hemisphere.
Comm. An eclipse is first computed for the primary
meridian. If an observer wants to know whether he lies
east or west of the primary meridian and to know the
Desāntara correction in time, the following procedure is to
be adopted. Let a lunar eclipse begin x ghatis after the
Sun-rise of the primary meridian. Let the observer note
the time y ghatis which have elapsed after Sun-rise at his
own place when the eclipse begins. Since a lunar eclipse