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

234 PAÑCASIDDHĀNTIKĀ X.6 Moon's orbit M R r Ecliptic S M' Fig. X. 2 What has been proved for the lunar eclipse can be taken for the solar eclipse also, with the neces- sary changes. The difference in motions should be here corrected for parallax and used. That this corrected difference is always less than the uncorrected will be clear, when we consider that always the parallax-corrected half duration is always greater than the uncorrected, which we have already proved. Therefore it is clear that by multiplying the “corresponding minutes” by the uncorrected half duration, and dividing by the parallax-corrected half duration, will give the parallax-corrected “corresponding minutes”. It is also clear that in the case of the solar eclipse we must use in the proof the parallax-corrected latitude in the place of the uncorrected latitude, the Sun for the Moon, and the Moon for the Shadow. When this is done, the proof is exactly similar to that for the lunar eclipse. Another thing is to be noted. The Hindu astronomers took the amount of eclipse at full moon or corrected new moon as the maximum and called it the magnitude, (grāsa-pramāṇa), though actually this is only very nearly the maximum and the actual maximum occurs a little earlier or later. If we take this full or new moon itself for doing the present work, since the time interval is zero, and thereby the ‘corresponding minutes’ are also zero, the latitude itself becomes the distance between the centres. Therefore we got that the amount eclipsed in this case (i.e. the magnitude) is to be got by subtracting the latitude of full or corrected new moon, from the half sum of the angular diameters, as already given. Now for the readings: vāñcchitanāḍī (‘desired time’) is meant here the interval in time from the full or new moon, either before or after. But TS have taken the expression to mean ‘the desired point of time’, and in order to get the meaning of ‘interval’ that is wanted for use, have emended the already correct sthitiliptāstābhyas tat into tatsthitiliptāvivarāt, which is unnecessary. Another thing must be said here. If the reading had been tithiliptāḥ instead of sthitiliptāḥ given by the manuscripts and accepted by us, it would have been better; for this would mean the minutes of tithi, as indeed these are, being part of a tithi by nature.