पृष्ठम्:स्फुटचन्द्राप्तिः.djvu/१६

I N T R 0 0 U C T I 0 N (OBJECT OF THE WORK 1method which would enable one to compute True Moon at in tervals of about 40 minutes cach, throughout the day. Now, amongst the celestial bodies, the Moon has not only the fastest motion, of about 13० per day, but also the greatest variation in motion. On account of this, True Moon for any specific moment if calculated by the rule of three using its true position and motion, at sunrise, as is generally done in the case of the other planets, cannot be expected to give correct results, the possibility of error being as large as 10 windikas. Even if the calculation is done using its true position and m10tions at sum rise and Sunset, the results obtained would still be far from acc:1rate. Accurate results can be obtained only by the Second or third differences, which, however, would entail inordinate labour. The method described in the present work obviates this labour and makes it possible to read out from a chart the True longitude of the Moon accurately at nine times a day, at intervals of a little over six and a half 74lka.s (2 hrs. 40 min.). From the True Moon at the quarter (40 min.) of these intervals, the True Moon at any moment falling within any such 40-minute-interval can be calculated by the rule of three, to get remarkably accurate results The fact that calculations are made correct t0 seconds adds to the accuracy of the results Certain peculiarities of the popular Moon-sentences (C011dra wakyas) of the Kerala astronomer Vararuci have provided the clue to our author for devising the meth0d described here. The said sentences comprise of 248 expressions couched in the Kat0payindi motation and give the longitudinal positions of the Moon for cor। secutive days contained in 9 ful11umar anomalistic cycles of 27 days, 33 7alikas and 16-24/55 winadikas each. These Ca11dra1akyas can be used from the moment when the amormally is zero, '.e., from the com junction of the Moon and its Higher Apsis (Candra-Turig८-yoga),