THE surya' siddha'nta, &c. 543 



cannot exceed six signs; if we divide this quantity, 

 by the number of years supposed now expired, we 

 shall have '^^^, = 0s 0° O' 0",1, or one tenth of a se- 

 cond, for the greatest possible difference that could 

 ari^e between the real mean annual motions of the 

 planets as determined by JLuropean astronomers, and 

 those which it would be necessary to employ, 

 reckoning from the epoch thus assumed, as M'ould 

 give the positions of the planets at present, with the 

 satne degree of accuracy, as the most modern of 

 European tables. 



7. It must therefore appear obvious, that the 

 further back an epoch of mean conjunction is as- 

 sumed, the nearer should the annual motions to be 

 thence adduced, agree with the real mean annual 

 motions, determined from actual observations: And 

 on the contrary, the nearer such epoch is assumed to 

 our own time, the greater the difference will be; 

 unless a point of time is found by computation, at 

 which the planets w^re either in a line of mean con- 

 junction, or so near, that the difference, when divided 

 among the years expired, would not sensibly affect 

 the mean annual motions to be thence derived : but 

 in this case, it is necessary that the Sun and Moon, 

 should be in a Hue of mean conjunction at the as- 

 sumed epoch : or at least very nearly so, in propor- 

 tion to the distance of time back ; for otherwise, the 

 computed times of conjunctions, oppositions, and 

 eclipses, of these luminaries, would not agree with 

 observation, for any considerable number of years. 



8. Upon this principle, the epoch now commonly 

 called the commencement of the Call yug^ appears 

 to have been fixed on, by Varaha and some other 

 Hindxi astronomers since his time : for, though the 

 planets were not then actually in a line of mean 



2 M 4 conjunction. 



