पृष्ठम्:महाभास्करीयम्.djvu/२५३

168 ECLIPSES diminish and increase the time of apparent conjunction as obtained by the method of successive approximations. Then are obtained the (approximate) times for the first and last contacts respectively. Proceeding with them, calculate the (ten) Rsines (for the Sun and the Moon), etc., (and obtain the nearest approximations to the lambanas for the times of the first and last contacts). Always add, in the case of a solar eclipse, the nadis of the difference between the lambanas for the first con- tact and the apparent conjunction to the sthityardha : (the result is the sparsa-sthityardha). Also add the (nadis of the difference between the) lambanas for the apparent conjunction and the end of the eclipse to the sthityardha : the result is the mokṣa-sthityardha. The sthityardhas thus obtained are very accurate I say this raising my hands aloft (i.e., with firm determination). When the first contact and the apparent conjunction occur in different halves (eastern and western) of the celestial sphere, then the entire lambana (in nadis) for the time of the first contact is added to the 'sthityardha. Similarly, when the last contact and the apparent conjunction occur in different halves of the celestial sphere, the entire lambana (in nadis) for the time of the last contact is always added to the sthityardha. The same procedure is also adopted when the apparent conjunction occurs at noon. The term sthityardha means "half the duration (of an eclipse)", The sparsa-sthityardha is the interval of time between the first contact and the apparent conjunction. The mokṣa-sthityardha is the time-interval bet- ween the apparent conjunction and the last contact. A rule for the determination of the vimardardha : 40. The nadis of the vimardärdha are to be determined from the square root of the difference between the squares of (i) the difference between the semi-diameters of the eclipsed and eclipsing bodies and (ii) the Moon's latitude (corrected for the nati).