Indian Science and Technology in the Eighteenth Century: Some Contemporary European Accounts c9.217

c9.217

x = 2 e sin . φ + (2 e³ sin . 3 φ)/3 + (2 e⁵ sin . 5 φ)/5 + & c. then 77. This method of calculation is so nearly exact, that even in the orbit of Mars, the equation calculated from the mean anomaly, rigorously on the principle of his angular motion being uniform, about a point distant from the centre, as described above, will rarely differ a minute from that which is taken out from the Indian tables by this rule. It was remarked, (§37) that it is not easy to explain the rules for finding the argument of the equation of the centre, for the planets. What is said here explains fully one part of that rule, viz. the correction made by half the equation *manda*; the principle on which the other part proceeds, viz. the correction by half the equation *schigram*, is still uncertain.