Indian Science and Technology in the Eighteenth Century: Some Contemporary European Accounts c9.39

c9.39

24. The moon’s mean place, for the beginning of the Calyougham, (that is, for midnight between the 17th and 18th of February 3102, B.C. at Benares), calculated from Mayer’s tables, on the supposition that her motion has always been at the same rate as at the beginning of the present century, is 10ˢ, 0°, 51′, 16″.³⁵ But, according to the same astronomer, the moon is subject to a small, but uniform acceleration, such, that her angular motion, in any one age, is 9″ greater than in the preceding, which, in an interval of 4801 years, must have amounted to 5°, 45′, 44″. This must be added to the preceding, to give the real mean place of the moon, at the astronomical epoch of the Calyougham, which is therefore 10ˢ, 6°, 37′. Now, the same, by the tables of Tirvalore, is 10ˢ, 6°, 0′; the difference is less than two thirds of a degree, which, for so remote a period, and considering the acceleration of the moon’s motion for which no allowance could be made in an Indian calculation, is a degree of accuracy that nothing but actual observation could have produced.