MANJULA'S MOON'S EQUATION original not only from this but also from other considerations. It sought to correct the constants as were obtained from the Babylonian and the Greek systems as has in some cases been shown already. Manjula's Second Equation of the Moon (932 A.D.) We now take up in detail Manjula's second equation of Moon. It is, however, necessary to say something about his first inequality. This is given in the form -488 sin (nt-a') 488 96+ 120 cos (nt--a') where nt stands for the Moon's mean longitude, a-that of the apogee. The modified form is 1.15 degrees. 488° 96 Hence when nt-a'-90°, the equation showing an excess of 4' over the modern value. It is further necessary to modify the expression for the Moon's modern form of the equation by chang- ing a to 180°+a, as in ancient Indian astronomy anomaly is measured not from the perigee but from the apogee. 1. इन्दूच्चोनार्ककोटिघ्ना गत्यंशा विभवा विधोः | गुरषो व्यकेंन्दुदोः कोट्यरूप पंचाप्तयोः क्रमात् ।। फले शशाङ्क--तद्गत्योर्लिप्ताथे स्वर्णयोर्वधे । ऋणं चन्द्र धनं भुक्तौ स्वर्ण सान्य वधेभ्यथा ॥ -5°4'-304' -301' sin (nt-a)+13 sin 2(nt-a)...... -152' sin (nt-0) cos (8-a)+40' sin 2(nt-0)+... Manjula's lines giving the second equation are The (mean) daily motion of the Moon diminished by 11° and multiplied by the "cosine" of the longitude of the Sun diminished by that of the Moon's apogee is the multiplier of the "sine" and the "cosine" of the longi- tude of the Moon diminished by that of the Sun, divided severally by 1 and 5. The results taken as minutes are to be applied negatively and positively to the Moon and to her daily motion if the quantities multiplied together are of opposite signs and in the reverse order if they are of the same sign. -11, 12
