Investigators will find that, contrary to the assumptions of some critics of Eastern chronology, a "year" does not mean a day, nor a month--although it is sometimes called "a day of the gods" in Eastern writings. One of the first things to arrest attention in the _Sûrya-Siddhânta_ is that in a "great age" of 4320 thousand years there are exactly forty revolutions of the Earth's apsides, one revolution of which occupies 108 thousand years. (Young's _General Astronomy_, § 199.) The line of apsides is the major axis of the Earth's orbit. Here we glimpse a basic connexion between the great cycles of time and the apsidal revolutions. Let us quote a few aphorisms from Book I of this ancient work. 27. By their [the planets'] movement the revolution is accounted complete at the end of the asterism Revatî. 29. In an age the revolutions of the Sun ... are 4,320,000. 30. Of the Moon 57,753,336. 31. ... of Jupiter 364,220. 32. ... of Saturn 146,568. 33. Of the Moon's apsis 488,203. Of its node, in the contrary direction 232,238. 34. Of asterisms 1,582,237,828. 36. ... From rising to rising of the Sun are reckoned terrestrial civil days. 37. Of these there are in an age 1,577,917,828. Of lunar days 1,603,000,080. From these figures we find the mean value of the sidereal year during a cycle of 4320 thousand years to be 0.002403 of a day longer than at present, which of course means that there are slow changes in the length of the orbital major axis. There is a point worthy of attention regarding the asterism Revatî, to which these revolutions are referred, and which is thus seen to mark the origin of the Hindû movable zodiac. The precise star has either disappeared, or has not, so far, been publicly indicated. But the place of the origin was carefully calculated in 1883, and found to have a longitude of about 20.5 degrees. Again, from the numerous facts connected with the important epoch of 3102 B. C., which marked the beginning of the current cycle of 432,000 years (See _Traité de_ _l'Astronomie Indienne et Orientale_, by M. Bailly, M. Acad. Franç., 1787), its place was about five degrees westward of the other. This shows it to have a positive movement of 4´´ per year, giving one complete revolution in 324,000 years.