10 Sjya-Shahbfd. 9. When the Sun's longitude is greater than that of the meridian ecliptic-point (madhydrene), subtract the parallax in longitude from the end of the lunal' day ; when less, add the same vepeat the process until all is fixed The text so perfinaciously rea neridian ecliptic-point (wategy ) whero we should expect, and ought to have, central ecliptic-point {tribkhortagh), that we are almost realy to guspect it of meaning to desig. nate the latter point by the foncr noneIy is sufficiently clear that, whenever the Sun and moon re to he ynrd of the eutrol ecliptic. point, the effect of the parallux in longitude will be to throw the noon forward on her orbit beyond the sun, and so to coubt the time of apparent to precede that of real conjunction na the contrary Imein the eastern hemisphere, the pazalax, in time, is subtractive le in he Western it is additive. But a single calculation und application of the orrection for pnrallax is not enough; the moment of apparent conjunction nust be found by a . series of succcasive approximations since४ jt, fol instance, the moment of Arue conjunction is 250 2 and the calculated paPallaux in longitude for that moment is 2" 21", the parent end of the unur day will not be at 27 23" , beenuk® at the latter time the pralax will be ent than deferring accordingly still fartho¥ {he time of onjunction; and so on. 'ho commentary explains the method of procedure more fully, as ollows
- ox the nonent of true conjunction in longitudle e; eu}uto the parallax in
longirao, and apply it to that moment : for the time thus found colculate the parallag new , and apply it to the moment of true conjunction : again , for the time found as the result of this process, calculate the parallax, and apply it s beforo; and so proceed, until moment, is arrived at, nt which the difference in actual longitude according to the motions of the two planets, will just equal and counterbat the paralax in longitude The accurney of this approximative process cannot but be somewhat impaired by the circumstanco that, while the pluralkx is reckoned in difiter ence of tnean motions, the corrections of longitude must be made in true motions. Indeed, the reckoning of the horizontal parallax in hims as 4 nadis, whatever be the rate of Trotion of the sun and moon, is one of tho most palpuble among bhe many errors which the Hindu process involves To ascertain the moment of apparent conjunction in longitude, only the purullax in longitude requires to be known but to determine the time of occurrence of the other phases of the eclipse, it is necessary to take into account the parallax in latitudehe ascertainment of which is accordingly made the subject of the next rule. 10. If the sine of ecliptic zenith-distance (d?ll$kend) be Imultiplied by the difference of the mean motions of the sun and