पञ्चसिद्धान्तिका (आचार्य वराहमिहिर - सूर्य, रोमक, पौलिश, वासिष्ठ एवं पितामह सिद्धान्त)

146 PAÑCASIDDHĀNTIKĀ V. 7 what the Siddhānta gives is only approximate, though easy to do, and for greater accuracy, we have to do a lot of work like calculating the Great gnomons of the Moon and the Sun etc. Example 3. Represent graphically the Moon of example 1. There, we are given, latitude of the place = 30°N, the Moon’s ayana is northward, and its latitude 4°S, and we get the difference in longitude = 15°, and the difference in declination = 5°. Horizon South North To Sun S A Fig. V. 5 From the data given above: i. The aṅgulas of elevation due to the latitude of the plane = 30 × 2 ÷ 15 = 4. ii. Aṅgulas of illumination = 15 ÷ 12 = 1¼. iii. Koṭi = 5° − 4° = 1°, and ∴ 1 aṅg., the Sun being to the south, (because it is evening observa- tion, and Moon’s ayana and lat. are of diff. direction). iv. Hypotenuse = 15 aṅgulas. v. Bhuja = √225-1 = nearly 15 aṅgulas. vi. Representation: Fig. 5: (Scale 1' unit = 6 aṅg.) It should be remembered that the fig. is intended only for the appearance of the Moon, with the illumination, and elevation of the horns represented on it, and none else. The line DGEFD is the part illuminated, D and E being the tips of the horns. Actually the Sun is down, on the line MF.