The Positive Sciences of the Ancient Hindus c5.s7.4

c5.s7.4

Bhâskara (1150 A.D.), in computing what he calls the “instantaneous” motion (तात्कालिकी गति) of a planet, compares its successive positions in two successive instants, and regards the motion as constant during the interval, which he conceives to be indefinitely small (त्रुटिकाल). This is equivalent to the determination of the differential of the planet’s longitude, and the process bears “a strong analogy” (to quote the words of Mr. Spottiswoode, the Astronomer Royal) “to the corresponding process in modern mathematical astronomy.” I have elsewhere shown that Bhâskara’s process was not merely analogous to, but virtually identical with, that of the Differential Calculus, Mr. Spottiswoode’s cautious reservation having been due to his want of acquaintance with the original and the insufficiency of the materials placed before him (*vide* pp. 78–79 *supra*).