Time and science have justified the conjectures and predictions of the Roman sage: the telescope has opened new worlds to the eyes of astronomers; and, in the narrow space of history and fable, one and the same comet is already found to have revisited the earth in seven equal revolutions of 575 years. The first, which ascends beyond the Christian era 1767 years, is coeval with Ogyges, the father of Grecian antiquity. And this appearance explains the tradition which Varro has preserved, that under his reign the planet Venus changed her color, size, figure and course; a prodigy without example either in past or succeeding ages. The second visit, in the year 1193, is darkly implied in the fable of Electra, the seventh of the Pleids, who have been reduced to six since the time of the Trojan war. That nymph, the wife of Dardanus was unable to support the ruin of her country: she abandoned the dances of her sister orbs, fled from the zodiac to the north pole, and obtained, from her dishevelled locks, the name of comet. The third period expires in the year 618, a date that exactly agrees with the tremendous comet of the Sibyl, and perhaps of Pliny, which arose in the west two generations before the reign of Cyrus. The fourth apparition, 44 years before the birth of Christ, is of all others the most splendid and important. After the death of Caesar, a long-haired star was conspicuous to Rome and to the nations, during the games which were exhibited by young Octavian in honor of Venus and his uncle. The vulgar opinion that it conveyed to heaven the divine soul of the dictator, was cherished and consecrated by the piety of a statesman; while his secret superstition referred the comet to the glory of his own times. The fifth visit has already been ascribed to the fifth year of Justinian, which coincides with the 531st of the Christian era. And it may deserve notice that in this, as in the preceding instance, the comet was followed, though at a longer interval, by a remarkable paleness of the sun. The sixth return, in the year 1106, is recorded by the chronicles of Europe and China: and in the first fervor of the crusades, the Christians and Mahometans might surmise, with equal reason, that it portended the destruction of the infidels. The seventh phenomenon, of 1680, was presented to the eye of an enlightened age. The philosophy of Bayle dispelled a prejudice which Milton's muse had so recently adorned, that the comet from its "horrid hair shakes pestilence and war." Its road in the heaven was observed with exquisite skill by Flamsteed and Cassini: and the mathematical science of Bernoulli, Newton and Halley, investigated the laws of its revolutions. At the eighth period, in the year 2355, their calculations may perhaps be verified by the astronomers of some future capital in the Siberian or American wilderness.