Jain Journal 1984 01

Author(s): Jain Bhawan Publication
Publisher: Jain Bhawan Publication

Page 17

JAIN JOURNAL
(diurnal circle on Summer solstice day). Having known the length of Sun's annual course (366 days) and following the notion that each of the extreme solar mandalas is traversed over only once during Sun's annual course, total number of solar mandalas was taken to be * +1 i.e. 184. N (=184-Nj) was easily calculated to be 119. Then D, might have been theoretically computed through relation (7). Further they employed a simple linear zigzag function to distribute the total north-south stretch 510 Yojanas between extreme solar mandalas uniformly among all the
48 solar mandalas. Thus NFD increases by 2-** - Yojanas per solar mandala from innermost solar mandala upto outermost solar mandala and vice versa. This exhibits their inefficiency to grasp the real variation in Sun's declination or NPD of solar mandalas as they understood it in their terms.
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Now let us make a further probe into the relationale of computation of NPD of solar mandalas. It may be recalled that
= Radius of Jambudvipa
50000 y Radius of the mount Meru's base on flat earth = 5000 y
It may be recollected here that as per our exposition of Jaina tentative astronomical model of Meru, true axis of earth passes along the hypotenuse of the approximate cone (made up of frustrum of cones) of Meru and thus the tentative axis of Meru passes through the earth at a distance of 5000 y (radius of base of Meru on flat earth) from the true axis of earth. And on the other hand, the innermost solar mandala (Sun's diurnal circle on Summer solstice day) is situated 180 Y inside Jambudvipa.
NPD of the innermost solar mandala or its shortest distance from periphery of Meru's base on flat earth
=(Radius of Jambuvdipa--radius of Meru's base on flat earth)
- distance of innermost solar mandala from periphery of Jambudvipa. =(50000—5000)y—180 Y =Numerically 44820 y.....
..............(9)
It may also be recalled that the tentative axis of Meru lies on the circumference of samatala bhūmi (earth having plane surface denoting circular area with centre at the projection of pole of ecliptic)12 On
12 Sharma, S. D. and Lishk, S.S. (1975), 'Latitude of the Moon as determined in Jaina
Astronomy', Sraman, Vol. 27, No. 2, pp. 28-35 (Varanasi).