38 Multiply this blujahala by the 3ghrakarr०, which is equal to radius (i.e., 3438') and divide by the (3) + or – sign being taken according as the 3gbrakendra is in the frst and fourth or second and third quadrants. Thern find the corresponding arc. Add half of it to or subtract that from the mean longitude of the planet, already corrected for half the bhaja than 180° From the result thus obtained subtract the longitude of the planet's maा। doca (apoge) : this gives the mandakerudra. Find the corresponding bluja, and therefrom calculate the bhujळ2hala by applying the formula (1) above Subtract this blujahala from or add that to the mean longitude of the planet (as corrected for the longitude, bhujantara and caru corrections), according as the mandak८rudra is less or greater than 180° : this gives the true-mean longi tude of the planet. Subtract this true-mean longitude from the longitude of the planet's 3ghroc८० : this gives the sigraटाdra. Find the corresponding bluja, and therefrom, by the application of formula (2) above, calculate the tained affresh by formula (3). Then find the corresponding arc, and add that to or subtract that from the true-mean longitude of the planet, according as the 51ghralk८nda is less than or greater than 180". The result thus obtained i the true longitude of the planet for true sunrise at the local place. For the Hindu epicyclic theory on which the above procedure is based, see my notes on MBl, iv. 40-44 A rule relating to the determination of the true (geocentric) longitudes of the inferior planets, Mercury and Venus 37(ii)-39. The method used in the case of Mercury and Venus is being described now First add or subtract half the arc corresponding to the ॐgh72}}|hala in the reverse order (i.e., according as the 3ghral८ndra is in the half-orbit beginning with Libra or in that beginning with Aries) to or from its own marud0८. Whatever correction is (then) derived from that (corrected) 7107do८a should, as a whole, be applied as correction to the mean longitude of the In the case of Mars,Jupiter and Saturn, the true-mean longitude is roughly the true heliocentric longitude and the true longitude, the true geo centric longitude.
