Among the historians of Indian astronomy, John Bentley seems to be first to stress, nearly two hundred years ago, that yuga and kalpa, which form the basic time-divisions used for traditional astronomical computations in India, are not historical but astronomically interpolated. Bentley says that a division of time simply into the four yugas, viz. Krta, Tretā, Dwāpara and Kali, was introduced in 204 B.C. “It appears,” as Bentley surmises, “that at, or about this period (204 B.C.), improvements were made in astronomy; new and more accurate tables of the planetary motions and positions were found, and equations introduced. Beside these improvements, the Hindu history was divided into periods, for chronological purposes....The period immediately preceding the inventor was called the first, or Kali yuga; the secojid or next, was called the Dwāpara Yuga; the third was called the Tretā Yuga; and the fourth, or furthest back from the author, was called Kṛta Yuga and with which the creation began. The end of the first period, called Kali was fixed by a conjunction of the Sun, Moon and Jupiter, in the beginning of Cancer, on the 26th June 299 B.C. This was called the Satya Yuga, or true conjunction, and is the radical point from which the calculation proceeds” (Bentley 1823, p.61-62).