86 That is, if the longitude of the Moon minus the longitude of the Sun be demoted by D, then (1) If the !ight half9f the month, the illuminated part of the Moon 6876 if D) < 3 signs; and [[R-+ Rsim (D- 90०)] x Moon's true diameter 6876 (ii) in the dark half of the month, the unilluminated part of the Moon Rversin (D-180°) x Moon's tr॥e diameter 6876 [R-+Rsin (D-270°)] x Moon's true diameter 6876 ifD) > 9 signs.
- Moon's true diameter' means “Moon's. angular diameter in minutes '
See supra, dth. TV, starm2a 5 For the rationale of these formulae, see my notes on MBh, wi. 5 (ii)-7 Verses 8-17 relate to the elevation of the horms of the Moon in (१uarter of the lumar month. the first A rule regarding the determination of the Moon's saikuagra at 8. From the 25us intervening between the Sun and Moon (corrected for the visibility corrections) and from the Moon's earthsine and ascensional (Moon's) altitude; and from that find out the (Moon's) 5aikugra, which is always south (ofthe rising-setting line of the Moon). The 05us intervening between the Sun and the Moon (corrected for the visibility corrections) are the ८5us to elapse before moonset. To obtain these 4945, one should increase the above longitudes of the Sun and the Moon both by six signs and find the obligue ascension of the portion of the ecliptic lying between the two positions thus found The Moon's earthsine is the portion of the Moon's diurnal circle intercep ted between the local and e१uatorial horizons. The Moon's ascensional differ