पृष्ठम्:महाभास्करीयम्.djvu/२४५

160 BCLIPSES When the declination of the meridian-ecliptic point and the local latitude are of like direction', take their sum; in the contrary case, take their difference; (and determine the Rsine of that sum or difference). This is the Sun's madhyajyā which has the same direction as the above sum or difference. In the case of the Moon, take the sum or difference of the local latitude, the declination (of the meridian-ecliptic point), and the (Moon's) latitude (corresponding to the meridian -ecliptic point) on the basis of likeness or unlikeness of direc- tion; and then determine the Rsine of the resulting arc. This is the (Moon's) madhyajyā, which has the same direction as the resulting arc.² The Sun's madhyajya is the Rsine of the zenith distance of the meri- dian-ecliptic point. The Moon's madhyajya is the Rsine of the zenith distance of the meridian point of the Moon's orbit. A rule for the determination of the drkksepajyas of the Sun and the Moon : 19. Take the product of (the Sun's or Moon's) own madhyajya and udayajya, then divide (the product) by the radius, and then take the square (of the quotient). Subtract that from the square of the (own) madhyajya : the square root of that (difference) is known as (the Sun's or Moon's) drkkṣepajya.³ 1 The direction of the local latitude is always south; the direction of the declination of the meridian-ecliptic point is north or south according as the meridian-ecliptic point is to the north or south of the equator. The rule for the Moon's madhyajya is approximate, because the arcual distance between the points where the meridian intersects the ecliptic and the Moon's orbit is not equal to the Moon's latitude corres- ponding to the meridian-ecliptic point. 3 This rule too is approximate Brahmagupta. (See Br.Sp.Si, xi. 29, 30). as follows: Let Z be the zenith, M the and has been criticised by The rationale of the ru is meridian point of the ecliptic