184 



Dr. G. Tliibaut — On the Surynprajnapti. 



[No. 4, 



found that the first up to the fifth inclusive, and again the eleventh up to 

 the fifteenth inclusive are " surya-sammisrani," i. e., partly coincide with 

 solar circles, while the sixth up to tlie tenth do not coincide with solar circles, 

 the latter falling entirely into the intervals between the named lunar cir- 

 cles. To reproduce here all the details of the calculation would be purpose- 

 less. — That the preceding account of the moon's motion agrees with the 

 ideas of the author of the Suryaprajiiapti is to be concluded from the formulas 

 given in different parts of the work for the performance of certain calcula- 

 tions. Thus for instance the question is raised, in what ayana and what circle 

 each parvan takes place, i. e., how many ay anas have elapsed at the different 

 times when the moou enters into conjunction or opposition and in which 

 of the fifteen circles she is moving just then. This question is answered 

 by some ancient gathas quoted in the commentary, according to which the 

 calculation has to be made as follows. The constant quantity — the 'ii'^^Trsj — 

 which is to be used for the calculation of each parvan, is equal to 

 4 9 



1 -f — + , viz., of one of the circles described by the moon. 



67 3 L X 67 ' ^ 



This quantity is of course easily found by the following consideration. The 



moon which describes in one yuga 1,768 circles describes in one parvan 



—— — = 14 — circles and m one ayana Id — circles ; the difference or 

 124 31 •'67 



these two quantities is the above mentioned constant quantity. The rule 

 for finding the places of the parvans is now as follows : The way accom- 

 plished by the moon during one parvan being equal to the way accomplish- 



4 9 



ed during one ayana plus 1 + — + circles, take at first as many 



° ^ i ^ 67 31 X 67 ' ^ 



ayanas as the number of the parvan whose place is wanted indicates, multi- 

 ply then the constant quantity by the number of the jDarvan, and if the 

 13 



result exceeds 13 deduct it from this latter quantity (which subtraction 



13\ 



if necessary has to be repeated until the remainder is less than 13 — ) ; 



as often as this subtraction is performed as many unities are to be added 

 to the number of ayanas found above and — unless the subtraction leaves 

 no remainder — one additional unity is to be added ; add two to the remain- 

 der ; the resulting sum will indicate the circle in which the moon stands 

 at the parvan. Regarding this latter jDoint it is to be remembered that 

 the circles are to be counted from the innermost circle when the number of 

 the parvan is an even one and from the outermost circle when it is an odd 

 one. To illustrate this let us take one of the many examples given by the 

 Commentator. Required the place of the moon at the fourteenth parvan. 

 Multiply at first one by fourteen, that means : fourteen ayanas have elapsed 



