114 



G. Thibaut — On tlie Siiri/aprajnctpti. 



[No. 3, 



obliged to deviate from the received tradition. For once the testimony of 

 the eyes was placed above old authorities. In the first place, the winter 

 solstice had so far receded from the beginning of Dhanishtha that the 

 change could not be ignored ; in the second place, it must have so happened 

 that at the time of the author of the Siiryaprajiiapti no new moon took 

 place together with the winter solstice, while — as we may presume — some 

 full moon happened to coincide or nearly to coincide with some summer 

 solstice. Accordingly the beginning of the yuga was changed. Faute de 

 mieux the summer solstice coinciding with full moon was taken as the 

 new starting-point, and the sun's place at the time was removed from the 

 middle of Aslesha which it had occupied in the old system to a point in 

 Pushya. The moon's place at the time of the summer solstice, being sepa- 

 rated from the sun's place by half the circumference, is then at the begin- 

 ning of Abhijit ; the latter point marks at the same time the sun's place 

 at the time of the winter solstice. 



The account given in the Siiryaprajnapti of the position of the sun at 

 the two solstices enables us to enter into a consideration of the approximate 

 time at which either the work itself or some older work on which it may have 

 been based was composed. The expression " approximate" is used on purpose 

 as the general difficulties besetting an estimation of this kind referring to 

 Indian astronomical works are well known, and as in our case special difficul- 

 ties arise in addition to them. As will be seen later on, the Siiryaprajnapti 

 throughout employs twenty-eight nakshatras of unequal extent, while the 

 Vedanga as well as the bulk of the later astronomical literature make use of 

 twenty-seven nakshatras of equal extent. The relation of these two systems 

 to each other necessitates a short excursus, for the starting-point of which 

 we take a passage in Bhaskara's Siddhanta Siromaiii (Grahaganita, Spash- 

 tadhikara, 71-74, p. 93 of Bapu Deva's edition) and a parallel passage from 

 Brahniagupta's Sphuta- siddhanta. The former of the two, translated, runs 

 as follows : 



" This method of finding the Nakshatras which has thus been taught 

 in a rough manner by the astronomers for the purposes of common life, I 

 shall now teach in an accurate form as it has been proclaimed by the rishis 

 for the purpose of processions, marriages, etc. The experts have declared 

 six (nakshatras) to have one portion and a half, viz., Visakha, Punarvasu 

 and the (four) nakshatras called dhruva ; six to have half a portion, w 22;., 

 the constellations presided over by the Sarpas, Rudra, "Vayu, Yama, Indra, 

 Varuna ; the remaining fifteen to have one portion each. The portion of 

 one nakshatra is called the mean motion of the moon (during one ahoratra). 

 The minutes of the circle lessened by the portions of all (the 27 mentioned) 

 nakshatras are the portion of Abhijit, lying beyond the nakshatra of the 

 "Visve Devas, etc." These statements are repeated in Bhaskara's own 



