192 



Dr. G. Tliibaiifc — On flw Surya/prajnopti. 



[No. 4, 



culations, rules for the performance of which are contained in the Siirya- 

 prajnapti itself as well as in a great ntimber of old karana-gathas quoted 

 by the commentator ; remarking at once that the rules contained in the 

 gathas presuppose exactly the same system as the rules of the Siiryapra- 

 jflapti itself. A comparison of these calculations with those contained in 

 the iyotisha-vedanga shows the extreme likeness and in many cases the 

 complete identity of the two sets' ; a result which supplies another reason 

 for looking on the Siiryaprajnapti as — in all essential points — a fair re- 

 presentative of Indian astronomy anterior to the period of the Siddhantas. 

 Several of these calculations have already been reproduced above inciden- 

 tally ; in the following a detailed account of the more important ones 

 among those not yet touched upon will be given. 



It appears that before the influence of Greek astronomy made itself 

 felt in India, the division of the sphere into 27 or 28 nakshatras was the 

 only one employed and that no independent subdivisions of the nakshatras 

 were made use of. This want was, however, supplied by a simple transfer 

 of the subdivisions of time to the nakshatras. In accordance with this 



.27 



principle the Smyaprajiiapti divides the sphere into 819 — muhiirtas, this 



being the duration of the periodical revolution of the moon, and allots to each 

 nakshatra a certain number of muhurtas according to its greater or smaller 

 extent. Fixed subdivisions of the muhiirta such as are commonly met in 

 Indian astronomical works are, however, nowhere employed by the author 

 of the Suryaprajilapti ; he a^^parently preferred to keep himself perfectly 

 free from restrictions of this kind and uses throughout those fractions of 

 the muhiirta only which were immediately suggested by the various cal- 

 culations in hand. From the general nature of the yuga it is manifest at 

 once which fractions will present themselves most I'cadily ; they are sixty- 

 seconds and sixty-sevenths (62 = number of synodical months in a 

 yuga, G7 = number of periodical months) and, whenever lunar months of 

 both kinds enter into the calculations, sixty-sevenths of sixty-seconds. 



One of the most important rules is that which teaches how to find the 

 place of the moon on any parvan. In the following the details of the 

 calculation furnished by the commentator will be stated in extenso, so that 

 at least one complete specimen of computations of this kind may be exhi- 

 bited. — If we wish to devise a rule for calculating the place of the moon in 

 the circle of the nakshatras at any parvan, we must at first find the 

 constant quantity — the dhruvarasi — entering a§ a multiplicand into all 

 calculations of this kind. This in our case is clearly the space passed 

 through by the moon during the lunar month, or more simply, because 

 entire revolutions which bring the moon back to the same place can be 

 neglected, the excess of the lunar syuodical month above the periodical 



