This section is from the book "The Brihat Jataka Of Varaha Mihira", by N. Chidambaram Aiyar. Also available from Amazon: Brihat Jataka of Varahamihira.
8. To the very yoga to which the maximum length of life has been assigned, certain Astrologers (a) have ascribed the life of a king. There is an evident error in this (b). Another error is, that persons born under the yoga of a sovereign are often found to live long and poor-
(a) Such as Badarayana and Yavaneswara. (b) The idea is that either most of the kings are short-lived or that most of the beggars live long.
The objection amounts to this:
That the very yoga which, according to Pindayurdaya is said to give a person the maximum length of life is considered by certain astrologers as Raja Yoga. In either case, several planets occupy their exaltation signs (vide Stanza 1, Chapter X1.) The Commentator considers this stanza too, not as the Author's, the objection raised being an absurd one. For, it is wrong to suppose that a particular yoga cannot be both a yoga for long life and one for the life of a sovereign. The other objection raised in the text is evidently a frivolous one and ought to be proved before it can be met.
9. According to Jeevasarma, the maximum number of years for each planet when in his exaltation sign and degree is one-seventh of the maximum length of human life - 120 years and 5 days - which is, 17 years, 1 month, 22 days, 8 ghatikas, 34.3 vighatikas = 17.14484 years, nothing omitted (a). In this view, Jeevasarma stands alone and is not supported by other authorities. According to Satyacharya, the planetary years are the same as the number of Navamsas passed over by each planet (b). This view has the support of many authorities.
(a) Just as in Pindayurdaya, the several reductions are to be made and then the resulting length of life ascertained.
(b) Counting from the Navamsa of Aries immediately preceding; so that, no planet can give more than 12 years.
10. According to Satyacharya, convert the Sphuta or longitude of the planet into minutes; divide the number of minutes by 200; the quotient will represent the number of Navamsas passed over by the planet from the first point of Aries. Divide this by 12, the remainder will give the number of Navamsas from the Navamsa of Aries and the number is also 'the number of years and fraction of a year for the planet.
Suppose, the longitude of the Sun to be 115 degrees, 13, minutes. This converted into minutes gives 6,913 minutes. Now, as a Navamsa contains 200 minutes, the number of Navamsas passed over by the Sun from the first point of Aries = 6913/200 = 34 113/200. Dividing this by 12, we get as remainder l0 113/200 Navamsas from the next preceding Navamsa of Aries. This, then, represents the years of the Sun which will be found to be 10 years, 6 months, 23 days and 24 ghatikas; and so on, for each planet.
11. Again, if any planet occupies its exaltation sign or is retrograde in its motion, the years assigned to it, shall be trebled; and if the planet be in its Vargot-tama or Navamsa or Swakshetra or Drekkana, its years shall be doubled. The above is a special feature, in Satyacharyar's Ayurdaya. In other respects, it resembles the Pindayurdaya - the several reductions (a) already referred to apply to the present case.
(a) These are Satru-Kshetraharana except for Mars, Astaugataharana except for Venus and Saturn and Chakrapataharana. The reduction known as Krurodayaharana does not apply to Satyacharyar's method (vide Stanza 12).
According to Garga, a planet occupying his Neecha-rasi loses one-half as stated in Note (g) to Stanza 2 excepting Chakrapataharana, which must always be done. Of the other reductions, if several have to be done to the years of a planet it will be sufficient, if the biggest one alone be made. So says Bhattotpala and no authority says otherwise. It is just the same whether the reductions are made first and the remainders are then doubled or trebled or the multiples made first and the reductions then applied to them.
12. According to Satyacharya, the years, months, etc, for the Lagna, the rising degree, are the same as the number.of Navamsas passed over (a) (as in the case of planets); but if the rising sign be powerful (b), then, the number of signs passed over represents the years, months, etc, (c). The reduction known as Krurodayaharana does not apply to Satyacharyar's method. In the case of the other reductions, the years given in the first stanza ought not to be employed (d).
(a) Beginning from the next preceding Navamsa of Aries.
(b) As stated in Stanza 19, Ch. I.
(c) As explained in Note (d) to Stanza 2 of this Chapter.
(d) That is, the special years of each planet according to Satyacharya's method ought to be subjected to the several reductions.
13. In the matter of Ayurdaya, the method of Satyacharya (known as Amsayurdaya) is the best (of the three methods of Ayurdaya). Objection is made to it, .on the ground, that the planetary years have to be multiplied several times (a). This is not so; where any period has to be multiplied by several numbers, it will be sufficient if the period is multiplied once and by the largest number (b).
(a) Suppose, Mercury to occupy sign Virgo which is his exaltation sign as well as his house. It would seem that under Stanza 11, Mercury's years should first be trebled and then doubled. Is this to be done? Again, suppose Mercury to occupy the last Navamsa of sign Virgo which is his Vargottama position. His years, it would appear, have to be doubled on that account. Already, we found that for being in his house, his years had to be doubled. The question is whether the years of Mercury have to be doubled twice. Again, suppose Mercury while occupying Virgo his exaltation sign is also retrograde in his motion for which his years have to be trebled. Are his years then to be trebled twice? No.
(b) If any period has to be doubled twice or thrice, it will be enough if it be doubled but once, and where the period has to be trebled twice or thrice, it will be enough if it be trebled but once. Again, if any period has to be both doubled and trebled, it will be enough if it be only trebled.
 
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