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

308 PAÑCASIDDHĀNTIKĀ XVII.11 Also, it is clear that it is not a substitute for any of the four steps because, if so the separate epicycle for Mercury will be useless. Note 2. It is clear that the rules given here are VM's own, to secure, in his opinion, better agree- ment with observation, because they are not given in the Ārdharātrika-pakṣa etc. and the original four steps are all in line with them, as also the modern Sūrya-Siddhānta and the Siddhānta Śiromaṇi. Note 3. The whole work of finding the true positions, especially of the star-planets is defective in Hindu astronomy, in that the equation of the centre of Hindu astronomy neglects the second, third, etc. terms, which is considerable in the case of the Moon, Mars, Saturn and Mercury, in which last case the second term is as large as 3°. In the case of Mercury and Venus it is applicable to the Sun, instead of their Śīghra which is really their mean. In the equation of conjunction, the Sun's true distance from the earth and true longitude should be used, instead of the mean distance and mean longitude, as is done in Hindu astronomy. On account of these defects, computation does not agree with observation, and all sorts of hotch-potch rules are given in different astronomical works. The disagreement among themselves would itself show that they are beside the mark. When these defects are remedied, the third and fourth steps alone would be necessary, the third step giving the heliocentric true planet; and the fourth step converting the heliocentric position to the geocentric. Note 4. In the case of Venus, there is another kind of defect. Its maximum eq. of cent. being small, it is confused with the Sun's, and the Sun's epicycle and apogee are given to Venus also. While its aphelion position is 290°, according to modern astronomy, its apogee is given as 80°, the same as the Sun's. Table of Heliocentric Star-planets at epoch. (For mutual comparison)

Planets	1 Modern astronomy	2 Sidd. Śiromaṇi	3 Later Sūrya Siddhānta	4 Earlier S. Siddhānta of PS	5 Vāsiṣṭha Pauliśa of PS	6 Interpolation in PS XVIII
Mercury	151°	148½°	166°*	148°		161½°
Venus	269°	268½°	264°	267°	269½°	269½°
Mars	75°	76½°	78°	75½°	83½°	83½°
Jupiter	9°	9½°	9°	8°	12°	9°
Saturn	122°	122°	123½°	122½°	120°	118°
For values in column (5) see their derivation in the Notes to ch. XVIII. All values have been com-
puted by me.

• This needs explanation: Perhaps the reading is śūnyāśvi in Sūrya Siddhānta I.31, which will reduce the degrees by 12. But the commentator Raṅganātha takes it as śūnyartuḥ.