गुप्त अभिलेख संग्रह (जे. एफ. फ्लीट - गुप्त सम्राटों एवं परवर्ती नरेशों के ऐतिहासिक पाषाण व ताम्रलेख)

(of time), then the so-called setting or rising of Jupiter, i.e. his heliacal setting or rising,
takes place.
To such a system, as is taught in this verse of Varâhamihira, and by no less than
eleven other authorities, as will be seen further on, or determining the commencement of
a saṁvatsara of the Twelve-Year Cycle, and of naming it, from Jupiter's heliacal-rising,
I would give the name of the heliacal-rising system, in order to distinguish it from
the other system in which the duration and name of a saṁvatsara of the Twelve-Year
Cycle are determined from the particular sign of the zodiac in which Jupiter stands with
reference to his mean longitude, and which latter system, to be mentioned more full,
further on, I would name the mean-sign system.
Now, the years of the Sixty-Year Cycle of Jupiter and of the Twelve-Year Cycle ac-
cording to the mean-sign system, are determined by his mean longitude,¹ which sometimes
differs from his apparent longitude by as much as fifteen degrees. But, as the disappear-
ance or reappearance of Jupiter is no imaginary thing, it is evident that it can be calcu-
lated, and is to be calculated, only according to Jupiter's actual place, that is, his apparent
longitude (or right ascension), and not from his mean longitude. And, consequently, the
beginning of each saṁvatsara of the Twelve-Year Cycle according to the heliacal-rising
system, depends on Jupiter's apparent longitude at the time of his heliacal rising.
One revolution of Jupiter, in the zodiac, is completed in about twelve years; and, in
twelve years, there are twelve revolutions of the sun (that is, of the earth). So that, in
this period of about twelve years, there are only eleven conjunctions of the sun and Jupiter.
Therefore, in twelve years there are only eleven heliacal risings of Jupiter.² The interval
between two risings is generally 399 days. And thus, in each cycle of the heliacal-
rising system, there are only eleven saṁvatsaras in twelve years; the duration
of each being about 400 days, and one saṁvatsara, determined by the circumstances of
the particular cycle, being altogether omitted.
The names of the lunar months are used as the names of the saṁvatsaras of the
Twelve-Year Cycle of Jupiter. And the names of these months are given to the saṁvat-
saras, in accordance with the particular nakshatra in which Jupiter's heliacal rising takes
place. Of the twenty-seven nakshatras, two are assigned to each of nine of the twelve
months; and three to each of the remaining three months. The rule for this is given in
the Bṛihat-Saṁhitā, viii. 2, — varshâṇi Kârttik-âdîny=âgnêyâd bha-dvay-ânuyôgîni ।
kramaśas tri-bhaṁ tu pañchamam upântyam antyaṁ cha yad varsham ॥,—“ the years
Kârttika and others (that follow) combine two nakshatras, from (the nakshatra) belonging

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¹ The mean longitude of a heavenly body is the longitude of an imaginary body, of the same
name, conceived to move uniformly with the mean motion of the real body.
² In his note on the Sûrya-Siddhânta, xiv. 17 (see the Rev. E. Burgess' Translation, p 271),
Prof. Whitney says that Jupiter “ would set and rise heliacally twelve times in each revolution, and