पृष्ठम्:महाभास्करीयम्.djvu/२७७

192 RISING, SETTING AND CONJUNCTION OF PLANETS of the Rsine of the zenith distance of the Moon for that time are prescribed to be made with the setting point of the ecliptic (taken for the Sun). The only difference in this case is that the time to elapse before moonset, instead of being found out from the asus intervening between the Moon and the Sun (as was done in the previous case), should be found out in this case from the asus intervening between the Moon and the setting point of the ecliptic, or, as the commentator Parameśvara says, from the asus intervening between the rising point of the ecliptic and the point six signs in advance of the Moon. The asus correspond to oblique ascension as in the previous case. Representation of the elevation of the lunar horns in the second quarter of the month : 19. (When the calculation relating to the elevation of the Moon's horns is made) after the eighth lunar day, the rising point of the ecliptic itself should be regarded as the Sun. And under that assumption should be made the calculation of the Rsine of the Moon's altitude, etc., with the exception of the calculation of the measure of the illuminated part (of the Moon's disc). A rule for the determination of the Rsine of the Moon's altitude to be used in connection with the elevation of the lunar horns : 20. The Rsine of the Moon's altitude should be calcula- ted from the asus intervening between the Sun and the Moon, or between the rising or setting point of the ecliptic and the Moon subject to the time of calculation, the asus being those obtained by applying the rule once and not successively. A rule telling that the above calculations pertaining to the elevation of the lunar horns relate to the first half of the month only: 21. In this manner, at sunset or any other time, with the help of the longitudes of the Sun, Moon and the Moon's ascending node, should be made this calculation relating to the Moon till the fifteenth lunar day: so has been said,