Page:Sewell Indian chronography.pdf/58

Veda contains a Nakshatra-kalpa and a Śānti-kalpa, both treating of the lunar mansions. (A. Weber. Hist. of Indian Liter. 1878, pp. 152–3.) They do not seem to have been in universal use for recording dates in all parts of India. Only one among the known inscriptions of the Gupta series, viz. that of Mānadēva of A.D. 705 mentions a nakshatra; and the majority of early dates found in the tracts where the lunar calendar was generally in use omit mention of them. But they are often stated and were regularly used in South India, from at least as early as the 10th century A.D., where they form one of the most important elements of the date, each day being named after the nakshatra current at sunrise. Mr. Sh. B. Dikshit believed that the nakshatras were, as early as 2000 B.C.,^[1] so well known that the names of the lunar months now in current use were, about that period, derived from them.

116. This derivation is indisputable. The ancient names of the lunar months were connected with the seasons, such as "hot," "rainy," "vapoury," and so on (which implies that the reckoning was luni-solar and not purely lunar).^[2] Afterwards the full-moon tithi (pūrṇimā) on which the moon became full when near the nakshatra Chitrā was called Chaitrī, and the lunar month which contained the Chaitrī pūrṇimā was called Chaitra; and so on. (Ind. Cal., §§ 41–44, pp. 24, 25, and Table.)

117. The sun's position with reference to the nakshatras is occasionally mentioned in inscriptions, though this could of course only be a matter of calculation and not of observation; but the solar months were, in most parts of India except the Tamil country, named formerly after the nakshatras, the zodiacal sign-names succeeding them.

118. The correspondence of the zodiacal signs with the nakshatras is exhibited in Table XXII., which was prepared, for the equal-space system and that of Garga, by Dr. Fleet, and for the Brāhma Siddhānta by myself. The ending-points of the nakshatras were also stated in the Table on p. 22 of the Indian Calendar in degrees, minutes and seconds; and for practical work by the ${\displaystyle a}$, ${\displaystyle b}$, ${\displaystyle c}$ system in terms of ${\displaystyle t}$ (the tithi-index) in Table VIII.

119. The moon's nakshatra, which is considered as an observed fact, is found from her apparent longitude, and our process of work for this is fully described in Ind. Cal., § 133, pp. 64, 65; while the practical and very simple method of actual work is given in §§ 156–158, p. 97. It amounts simply to this—In every process of work by the ${\displaystyle a}$, ${\displaystyle b}$, ${\displaystyle c}$ system for finding the lunar tithi current at a given moment, we have to fix the values at that moment of ${\displaystyle c}$ (the sun's mean anomaly), equation ${\displaystyle c}$, and ${\displaystyle t}$ the finally found tithi-index. ${\displaystyle n}$ being the nakshatra-index required (which gives us the moon's apparent longitude, and therefore her position with reference to the fixed stars of the nakshatra-belt) the formula is—

Thus, in the example given on p. 81 of the Indian Calendar, ${\displaystyle c=439}$, equation ${\displaystyle c=38}$, ${\displaystyle t=1463}$, and the work is—

The portion of the formula which gives the apparent longitude of the sun is ${\displaystyle (c\times 10)+7207-{\text{equation }}c}$, and calling this ${\displaystyle s}$ we have ${\displaystyle n=s+t}$. Though the formula is exceedingly simple, Dr. Schram has made

1. ↑ "Certainly not later than 1500 B.C. and not earlier than 4000 B.C." (S. B. D., Ind. Cal., . 24, n.)
2. ↑ The old names were occasionally used to a much later date, eg., in A.D. 437–8, 473–4, in the Mandasōr Gupta inscription. (Fleet, Gupta Inscriptions, p. 79.)