Indian Science and Technology in the Eighteenth Century: Some Contemporary European Accounts c10.16

c10.16

It is also generally reported that the Bramins calculate their eclipses, not by astronomical tables as we do, but by rules; now these rules, are either as exact as our methods, or not; if they are not, perhaps they may be some particular modes of applying the Chaldean ‘saros’ of 223 lunation, or the ‘neros’* of 600 years, which may be of use in making a near estimate of the times when eclipses may happen: If they be as exact as ours, or but nearly so, it is a proof that they must have carried algebraic computation to a very extraordinary pitch, and have well understood the doctrine of ‘continued fractions’, in order to have found those periodical approximations; this I am the more confirmed in because I have heard that the Bramins have different rules for computing eclipses and that those rules are more or less complex according to the requisite degrees of exactness; which entirely agrees with the approximation deduced from algebraic formulae, and implies an intimate acquaintance with the Newtonian doctrine of series. This at first sight may seem improbable, but will appear entirely consistent when we recollect that the Bramins have Arabic treatises among them, and that the Arabs are well known to have carried Algebra to a high degree of perfection: We are even told that they had a complete method of resolving cubic equations, and were likewise possessed of the 13 books of Diophantus, the 7 last are lost; in the 6 that remain he has carried the subject almost as far as we have, and therefore it is not impossible for the Bramins to have understood Algebra better than we do.