सिद्धान्तदर्पण (महामहोपाध्याय सामन्त चन्द्रशेखर सिंह - नग्न-नेत्र खगोल वेध एवं गणित महाकोश)

xxxiv सिद्धान्त दर्पण
inequalities, Tungantara, Pakshika and Digamsa, with
the maximum amounts of 2°40′, 38′12″, and 12′
respectively (S.D.VI.7).
For those who may be inclined to compare his
corrections, his method of applying them is briefly
described here. After the equation of centre
(maximum amount 5° 1′ 10″) has been applied to
the mean Moon, call the result Ist Moon M₁ Then
add to, or subtract from it, according as the anomaly
happens to be within the first six or the second six
signs.
160′ x Sin[A - (0+3)] Sin(M₁-0)
--------------------- x ---------
R R
Ist Moon motion
x ---------------
mean motion
where A stands for the Moon’s apogee, and 0
for the true Sun. The two signs (±) are to be taken
in the case of the light and dark halves of each lunar
month respectively. The result obtained is called the
2nd Moon, M₂.
To apply the Pakshika correction, take
M₂ - 0
------ = a+ b (say). Subtract b from 3 (Signs)
3 3 -
3
and take the less of two quantities, a and
(3 - b ) and say, it is y. Then sin2y is the

---

3 90
corection required. It should be noted that the
denominator (90) is not constant, but can be
obtained. The correction is to be added to, or
substracted from the 2nd Moon, as the latter lies
within the first or the second quadrature. Call the
Moon thus corrected, the third Moon, M₃-