"The Hindus attained a very high proficiency in arithmetic and algebra independently of any foreign influence." The romance of the composition of Lilavati - the standard Hindu textbook on Arithmetic by Bhaskaracharya - is very interesting and charming. It deals not only with the basic elements of the science of arithmetic but also with questions of interest, of barter, ofpermutatlOns and combinations, and of mensuration. Bhaskaracharya knew the law of gravitation. The Surya Siddhanta is based on a system of trigonometry. Professor Wallace says: "In fact it is founded on a geometrical theorem, which was not known to the geometricians of Europe before the time of Vieta, about two hundred years ago. And it employs the sine of arcs, a thing unknown to the Greeks." The 47th proposition of Book I of Euclid, which is ascribed to Pythagoras was known long ago to the Hindus and must have been learnt from them by Pythagoras."