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SEPTEMBER, 1910.)
BOOK NOTICES.
265
Nor do we know of any Hindu astronomer, king with reference to any fixed star, measures nearly or ordinary person, who bore the name Mathane, 8 hours in excess of 27 days, and so runs well into
the 28th day. or of any noteworthy astronomer who was named Madana. Does this book of Raja Mathan" The invention of the ecliptic, and the division of mean the Rījamārtanda, an astrological work
its circle into 360 degrees and so on, made it
practicable to measure distances : and, the princiwhich is attributed along with an astronomical
pal attention being still paid to the moon, the idea treatise entitled Rājamrigānka to king Bhõja of | was then entertained of noting its course with Dhari (A.D. 1042 ) P Or is it possible that regard to the ecliptic, and of referring the nak"Mathan" is in reality only & reminiscence of
shatras to the ecliptic for that purpose. In those " Meton"? In any case we should much like to
days, however, only mean motions of the sun and
the moon were recognized : that is, the sun and have the text of this book of “Raja Mathan ": the moon were believed (not simply assumed) to be especially because (see 115) it seems to teach the always travelling with absolute regularity of moveoriginal Motonic cyole, without any adjustment.
ment. Also, 360 degress are divisible conveni
ently by 27, but not by 28. And the length of In $-46, Mr. Irwin has given us, from the
the sidereal month is ncarer to 27 than to 28 Thandeikta, a system of the nakshatras - the days. Accordingly, as a matter of convenience, 80-called "lunar mansions" and " signs of the the number of the nakshatras was fixed at 27, lunar zodiao" - which is of a quite exceptional
by omitting one, Abhijit, lying rather closely
between two others; and the circle of the ecliptio nature. And in this connexion he has made a
was divided into 27 equal portions, each of 13° 20', remark, -namely, that "the most inodern system
some of which have in reality only a rather disin India is that of equal spaces, 13° 20' being ag- tant connexion with the stars from which they signed to each nekkat", which is liable to convey have derived their names. An advance in calcuan erroneous impression. The equal-space system
lative processes soon gave ability to compute the
course of the sun as well as that of the moon. is certainly the one which has survived and now
But the signs of the zodiac had not yet been prevails in India. It is, however, by no means the invented. So the divisions of the ecliptic, arrived latest by origin. Regarding the country in which at as indicated above, were applied to the sun also. the idea of the nakshatras had its origin, and re
And we find this oqual-space system of the
nakshatras used for both the sun and the moon garding the stars which constitute some of them,
in the Jyotisha-Vēdānga, the earliest known there may still be differences of opinion. But the Hindu astronomical work. Accordingly, 8 redevelopment of the matter appears to have been gards a point of terminology, though the nak. distinctly as follows:
shatrus are of lunar origin, and are now used moet
markedly in connexion with the moon, and may The nakehatras are certain conspicuous stars
from this point of view be fairly called " lunar and groups of stars which lie more or less closely
mansions and " signs of the lunar zodiac ", there along the course of the sun and the moon, and
is nothing exclusively lunar about them; and they consequently are more or less near to the ecliptic.
are still used, in subordination to the signs of the Now, the course of the sun with reference to the
zodiac, to note the course of the sun too. stars can only be determined by calculation, or, in a rough manner, by inference from the position of
Subsequently, attention was paid to the point the moon, and so could not be considered when
that the nakshatras or their principal stars, the the scienco of astronomy was still in a primitive
"junction-stars ", do not really lie at equal disstate. The case is quite different with the moon,
tances; and a refinement was made, in accordwhich can be watched from night to night through ance with which, the number of 27 nakshatras almost the whole of its course. A part, then, from being still retained, and the space of 13° 20' being other considerations, such as that the moon regu
preserved as the unit, there was devised a system lates the months, the succession of which attracte
of unequal spaces, of which some measure that notice far nuore readily than the succession of the
unit, others measure hall the unit, and others years determined by the sun, attention was measure one and a half times the unit. To this naturally paid first to the course of the moon. In system there became attached the name of an that early time, bowever, the ecliptic, with its early astronomer called Garga. divisions, had not been devised: and so the course After that, another refinement was made, and of the moon could only be noted by saying that there was devised a second system of unequal the moon was from time to time near to or in spaces which is exbibited in the Brahma-Bidconjunction or in a line with some particular star dhänta of Brahmagupta (written A.D. 628-29). or group of stars. Originaily, 28 such stars and The unit taken in this case was the mean daily groups of stars were used; because the sidereal geocentric motion of the moon, 13° 10' 35". The month, the period in which the moon makes e spaces of the Garga ayatem were recast accordcomplete circuit of the heavens round the earth | ingly. And the balance which remained over,
Moton (B.C. 432) is understood to have intercalated in the years 3, 5, 8, 11, 13, 16, and 19: 300, .. 9., Clinton, Pasti Hellenici, vol. 2 (third edition), p. 408. As is well known in connexion with the use of the "Golden Nambers" (an adaptation of his oyolo) to determine the date of Easter, it has been nooossary to roadjust the oyole from time to time, by obanging the years of intercalation. The Burmese are now intercalating in the years 2, 5, 8, 10, 12, 16, 19; the Arakanoso, in the years 2, 6, 8, 11, 14, 16, 19.
