A colony of Brahmins settled near the Imans, and in Northern Thibet, where in ancient times they established celebrated colleges, particularly at Nagraent and Cashmere. In these institutions the treasures of Sanskrit literature were supposed to be deposited. The Rev. Mr. Maurice was informed that an immemorial tradition prevailed at Benares that all the learning of India came from a country situated in forty degrees of northern latitude. Other writers are of the opinion that civilization proceeded from Arabia; that the old Cushite race carried commerce, letters, and laws to all the nations of the East. Which of these theories is true, if either, may not with certainty be proved at present; yet that in the far distant past a race of people existed whose achievements exceeded those of any of the historic nations may not be doubted. That the length of the year was calculated with greater exactness by an ancient and forgotten people than it was by early historic nations is proved by the cycle of the Neros. This cycle, which was formed of 7,421 lunar revolutions of 29 days, 12 hours, 44 minutes, and 3 seconds, or 219,146 days and a half, was equal to 600 solar years of 365 days, 5 hours, 51 minutes, and 36 seconds, which time varies less than three minutes from the present observations of the year's length. The length of the year as calculated by the Egyptians and other early historic nations was 360 days, which fact would seem to indicate that a science of astronomy had been developed in an earlier age which by the most ancient peoples of whom we have any historic records has been lost or forgotten. It has been said that if this cycle of the Neros "were correct to the second, if on the first of January at noon a new moon took place, it would take place again in exactly 600 years at the same moment of the day, and under all the same circumstances."(61) 61) Godfrey Higgins, Celtic Druids, ch. ii., sec. 14. The Varaha Calpa has the famous cycle of 4,320,000,000 years for its duration. This system makes the Cali Yug begin 3098 years B.C. A dodecan consisted of 5 days, and 72 dodecans formed a natural year of 360 days. According to the earlier calculations, 360 solar diurnal revolutions constituted a natural year. The doctrine of the ancients concerning these cycles is thus set forth by Godfrey Higgins: