ब्राह्मस्फुटसिद्धान्त (ब्रह्मगुप्त - शून्य, कुट्टक, बीजगणित एवं सम्पूर्ण २१ अध्याय सान्वय सटीक)

BHĀSKARA II ON INEQUALITY OF THE MOON 119 The reasons for his new equations are stated as follows:— When the Moon is situated at a quadrant ahead of the apogee and with the Sun at half a quadrant ahead of her, the maximum discrepancy (of 112′) is seen in the negative character. When the Moon is situated at three quadrants ahead of the apogee and with the Sun at half a quadrant behind her, the maximum discrepancy (of 112′) is seen in the positive character. When the eclipses of the Sun and the Moon take place at the apogee or the perigee of the Moon, the Moon as corrected by the equation of apsis is seen to be without any new correction called bīja. When the eclipses of the Sun and the Moon take place at the ends of the odd quadrants of the Moon's anomaly (measured from the apogee), the discrepancy is seen to be less by 34′. When the Moon is at the apogee, whether the Sun be ahead or behind her by half a quadrant, the discre- pancy amounts to be 34′. The same discrepancy of 34′ is observed when the Moon is at the perigee and the Sun is ahead or behind her by the same distance. Thus by analysis and synthesis, and by repeated obser- vations, this variable correction has been devised by me; let it be seriously considered by the learned.¹ Bhāskara here speaks of six cases and we consider them one after another :— The Moon's equations as modified to suit siddhāntas are given by −301′ sin (nt—α)+13′ sin 2(nt—α)...... −152′ sin (nt—θ) cos (θ—α)−40′ sin 2(nt—θ)+...... According to Bhāskara's Siddhānta - śiromaṇi. the Moon's equation of apsis = − (31° 36′ / 360°) × 3438′ sin (nt—α) = −301′ 46″. 8 sin (nt—α),