A History of the Kerala School of Hindu Astronomy (in Perspective) c9.s5.1

c9.s5.1

Of all heavenly bodies, the Moon has not only the fastest motion, but also the maximum changes in its velocity during the same day. Therefore, the computation of the Moon at some intermediate time during the day, if calculated on the basis of its true position and motion at sunrise or at sunset, as advocated in some *Pañcabodha* texts, would not give accurate results. An ingenious but facile method for the determination of the Moon at any time of the day with high accuracy has been evolved by the 14th century Kerala astronomer Mādhava of Saṅgamagrāma in his work called *Veṇvāroha*. He has also enunciated accurate moon-mnemonics, correct to the seconds, for being used in the *Veṇvāroha* method. His method seems to have caught the fancy also of later astronomers who have extended the method further to yield still more accurate results. At least four later works of this genre have been identified, they being *Candrasphuṭāpti, Veṇvārohakriya and Dṛg-Veṇvārohakriya, all anonymous, and Veṇvārohaṣṭaka of Puṭumana Somayāji.