1836.] 



On the Hindu Astronomical Tables. 



231- 



antiquity. And here, with regret, I differ in opinion from a learned and 

 illustrious astronomer, whose fate is a terrible proof of the inconstancy 

 of popular favour, who, after having honoured his career by labours 

 useful both to science and humanity, perished a victim to the most 

 sanguinary tyranny, opposing the calmness and dignity of virtue, to the 

 revilings of an infatuated'people, of whom he had been once the idol. 



" The Indian tables have two principal epochs which go back, one 

 to the year 3102, the other to the year 1491, before our era. These 

 epochs are connected with the mean motions of the sun, moon, 

 and planets, in such a manner, that, setting out from the position 

 which the Indian tables assign to all the stars at this second epoch, 

 and reascending to the first by means of these tables, the general con- 

 junction which they suppose at this primitive epoch is found. Bailly, 

 the celebrated astronomer, already alluded to, endeavours, in his Indian 

 Astronomy, to prove that the first of those epochs is founded on ob= 

 servation. Notwithstanding all the arguments are brought forward 



i with that perspicuity he knew so well to bestow on subjects the most 

 abstract, I am still of opinion, that this period was invented for the pur- 

 pose of giving a common origin to all the motions of the heavenly 

 bodies in the zodiac. Our last astronomical tables being rendered 

 more perfect by the comparison of theory with a great number of ob« 



I servations, do not permit us to admit the conjunction supposed in the 

 Indian tables; in this respect, indeed, they made much greater differ- 

 ences than the errors of which they are still susceptible, but it must be 

 admitted that some elements in the Indian astronomy have not the 

 magnitude which they assigned to them, until long before our era; for 

 example, it is necessary to ascend 6000 years back to find the equation 

 of the centre of the sun. But, independently of the errors to which the 



i Indian observations are liable s it may be observed, that they only con- 

 sidered the inequalities of the sun and moon relative to eclipses, in 

 which the annual equation of the moon is added to the equation of the 

 centre of the sun, and augments it by a quantity which is very nearly 



: the difference between its true value and that of the Indians. Many 

 elements, such as the equation of the centre of Jupiter and Mars, are 



j very different in the Indian tables from what they must have been at 



| their first epoch. 



" A consideration of all these tables, and particularly the impossi- 



i bility of the conjunction at the epoch they suppose, prove, on the con- 



| trary, that they have been constructed, or at least rectified, in modern 

 times. This also may be inferred from the mean motions which they 

 assign to the moon, with respect to its perigee, its nodes, and the sun, 

 which, being more rapid than according to Ptolemy, indicate that they 

 are posterior to this astronomer; for we know, by the theory of uni- 

 versal gravitation, that these three motions have accelerated for a 

 great number of ages." 



