Apart from these considerations it is open to doubt whether the week originated from the astronomical considerations that are held to have brought the week day into existence. It is generally taken that, for the constitution of the week, the division of the day into the nychthemeron or of twenty-four hours is absolutely necessary. As another consideration, the planets are supposed to be taken in the order of diminishing distances beginning with Saturn, appointing each of these planets to be the presiding deity of a particular hour of the day in rotation. At any particular date when the week got to be originated, reversing of the order with a view to bringing it in line with the twenty-four hours division would perhaps imply very much more knowledge of scientific astronomy than could have been possessed by the originators. Hence it would bear the conclusion that this probably is a later astronomical adjustment of an already existing week system. It would seem more reasonable to ascribe the origin of the week to causes other than astronomical, for which there is a considerable volume of evidence in Hindu literature. The week seems actually to have originated in a division of the month into quarters, and each quarter is taken roughly to be seven days, necessary adjustments following when the error got to be discovered. There were several such divisions known from Vedic times, as Dr. Shamasastri demonstrates1 clearly. That the week arises naturally from a division of the day into sixty periods as the Hindus have, comes out clearly from the following remarks of Professor Rawlinson.2 ' There is further no evidence to show that the Medes, or even the Babylonians were acquainted with the order of the planets which regulated the nomenclature of the days of the week. The series in question, indeed, must have originated with a people who divided the day and night into sixty hours instead of twenty-four; and so far as we know at present, this system of horary division was peculiar in ancient times to the Hindu calendar; the method by which the order is eliminated is simply as follows: - The planets in due succession from Moon to Saturn were supposed to rule the hours of the day in a recurring series of sevens, and the day was named after the planet which happened to be the regent of the first hour. If we assign then the first hour of the first day to the Moon we find that the 61st hour which commences the second day belongs to the fifth planet or Mars; the 121st hour to the second or Mercury, 181st to the sixth or Jupiter, the 241st to the third or Venus, 301st to the seventh or Saturn, 361st to the fourth or the Sun. The popular belief (which first appears in Dion Cassius) that the series in question refers to a horary division of twenty-four is incorrect; for in that case, although the order is the same, the succession is inverted. One thing indeed seems to be certain, that if the Chaldeans were the inventors of the hebdomadal nomenclature, they must have borrowed their earliest astronomical science from the same source which supplied the Hindus; for it could not have been by an accident that a horary division of sixty was adopted by both races.' Dr. Shama Sastri has attempted to prove that this division originated with the Hindus, while a school of Assyriologists would give the credit to the Babylonians.

1 Annals of the Bhandarkar Institute, for July, 1922, pp. 1-31.

2 Herodotus, I. 226.

Without labouring the point further we might proceed to the consideration whether we have any evidence of the Hindus having had any knowledge of the planets either generally, or in the week day order. It is now generally admitted that the division of the ecliptic into 27 constellations was known to the Hindus from Vedic times. It is not quite clear that they knew its division into the twelve houses of the zodiac. It seems inferable from the mention of the term Saura-masa of thirty l days and a half, and a few other details like Uttarayanam and Dakshinayanam, that some kind of division answering to the division of the zodiac existed among the Hindus in the fourth century B.C. The mention of the planets in the week day order in the Baudhayana Dharma Sutra is equally significant in this direction. This happens to occur in the first two books (actually in II. 5.9) of the Sutra which are regarded by the late Dr. Buhler as not having been tampered with to the extent that the later books are, and these Sutras, at least the genuine parts of them, are referable to the fourth century B. C. according to the same authority.1 The Sardula Karnavadana, which was translated into Chinese in the third century A.D. and' the framework of (which) avadana itself must be of great antiquity' according to its learned editors Cowell and Neil, not merely contains reference to the planets including Rahu and Ketu, but even a division headed Dvadasa-ras'ika, the twelve signs of the zodiac. This avadana contains a volume of astrological information which would warrant great astrological knowledge among the Hindus. In avadana 19 of the same work, called Jyotishka-avadana, there is a reference to an astrologer named Bhurika as having made a calculation and verified a prediction of the Buddha.2 It is hardly necessary to multiply references. In the face of these, it would be too much to postulate that the Hindus had no knowledge of astrology, or of the signs of the zodiac, or that they borrowed the week day from the Christian week in the age of the Guptas. It would be safer to hold with Buhler, 'I do not think it has been proved that every work that enumerates the rasis must be later than the period when Ptolemy's astronomy and astrology were introduced into India.'1 Prom the point of view of mere historical considerations, parts of India were very much more in contact with the Greek world of Asia from the time when Selucus I became king of Asia down to the end of the Kushans, and cultural elements like astrology or the week days, if they came from the West of India, had ample opportunities of coming into the country before the days of Paulus Alexandrinus, or even before the days of Ptolemy. In the present state of our knowledge of the cultural histories of India and of Western Asia respectively, it is too much to build on the available evidence to state categorically that any reference to a week clay in any work of literature ipso facto condemns it to a period posterior to the age Aryabhatta. Aryabhatta was born, according to his own statement, in A.D. 472-73 and composed his principal work in his 23rd year, i.e., A.D. 496-97. But the inscription of Budhagupta mentions the week day, Thursday, more than ten years before this. In the light of the evidence cited above, and

1 Chapter XX of the Artha Sastra, Shama Sastri's translation.

1 Sacred Books of the East, II, pp. xxiv and xliii.

2 lb., p. 263.

1 Buhler's Manu, p. cxvii, having regard to the uncertain character of the evidence offered I may be excused if I show myself to be somewhat sceptical, however regretfully, in regard to the conclusions of my esteemed friends Messrs. Swamikkannu Pillai and Kames-wara Ayyar, who have committed themselves, each in his own particular way, to the view that the Hindu knowledge of astronomy is post-Alexandrian in all its details. I do not exclude the possibility that Hindu astronomy, such as it was, was wrong in details and adopted corrections from the Greeks when Greek astronomy came to be fully known to them in the age of Aryabhatta, or somewhat later in that of Varahamihira. If I still persist in relying more upon historical considerations in my classification of Tamil literature, I hope I have demonstrated above, that I have good reason to support me in my position.

In concluding this introduction I must acknowledge my gratitude to the Council of Post-Graduate Teaching at the Calcutta University, and, to the University as a whole, for the honour they have done me in nominating me Reader. My acknowledgments are also due to my friend Professor D. R. Bhandarkar and several other members of the Calcutta University. My debt of obligation to Sir Asutosh Mookerjee is so great that I could hardly dream of acknowledging it adequately. I have dedicated the following lectures to him as in some measure expressive of my great esteem, without his permission. I trust that he will accept this token of my personal regard for him and the high esteem in which I hold his services to the cause of University Education in general and to Indian History and Culture in particular. I have great pleasure in acknowledging the assistance that Mr. R. Gopalan, B.A. Hons., the University Research Student working with me. rendered in the compiling of the index. I acknowledge with equal pleasure the ready courtesy of Mr. A. C. Ghatak, the Superintendent of the University Press, Calcutta, and the excellent manner in which he saw the work through the Press, which under his expert guidance proves to be very efficient.

Madras University:

26th March, 1923.

S. K. AlYANGAR.