(ii) The same according to the Khandakhadyaka = 29.5305874 days. MOON'S MEAN MOTION (iii) The same according to the Brahma-sphuja-siddhanta = 29.530582 days. (iv) The same according to Ptolemy-29 da. 31' 50″ 8′ 20″ in sexagesimal units 29.5305927 days The modern value according to Newcomb and Radau = 29.5305881 days. Hence the Khandakhadyaka mean length appears to be the closest approximation. The mean sidereal month must have been deduced from the mean synodic month and the year adopted. Hence no compari- son need be made of this element here. According to We will now consider the sidereal periods, the nodes and the apogee of the Moon. These are shown below:- Aryabhatiya Khandakhadyaka Brahma-sphuta - Sid- dhunta Sid. Per. of Moon's Apogee 111 3231,987079 da. 3231.987844 da. 3232.73411 da. Ptolemy 3232.617656 da. Modern values (Lockyer) 3232.37543 da. Sid. per. of the Ascending Node 6794.749511 da. 6794.750834 da. Inclination of the lunar orbit Indian value=4°30'. 6792.25396 da. 6796.45571 da. 6793.39108 da. Here also the Indian values show a closer approximation to the true values, Brahmagupta's figures representing the nearest approach. Other Constants have been more So far the Indian values of the constants accurate than the Greek ones; but as to the inclination of the Moon's orbit the Greek value is more accurate than the Indian value.
