Indian Science and Technology in the Eighteenth Century: Some Contemporary European Accounts c9.31

c9.31

19. Somewhat in the same manner, but by a rule still more artificial and ingenious, they deduce the place of the moon, at any given time, from her place at the beginning of the Calyougham.²⁷ This rule is so contrived, as to include at once the motions both of the moon and of her apogee, and depends on this principle, according to the very skilful interpretation of M. Bailly, that, 1,600,894 days after the above mentioned epoch, the moon was in her apogee, and 7ˢ, 2°, 0', 7", distant from the beginning of the Zodiac; that after 12,372 days, the moon was again in her apogee, with her longitude increased, 9ˢ, 27°, 48', 10″; that in 3031 days more, the moon is again in her apogee, with 11ˢ, 7°, 31′, 1″ more of longitude; and, lastly, that, after 248 days, she is again in her apogee, with 27°, 44′, 6″, more of longitude. By means of the three former numbers, they find, how far, at any given time, the moon is advanced in this period of 248 days, and by a table, expressing how long the moon takes to pass through each degree of her orbit, during that period, they find how far she is then advanced in the Zodiac.²⁸ This rule is strongly marked with all the peculiar characters of the Indian astronomy. It is remarkable for its accuracy, and still more for its ingenuity and refinement; but is not reduced withal, to its ultimate simplicity.