Page:Decline and Fall of the Roman Empire vol 4 (1897).djvu/458

434 by the piety of a statesman; while his secret superstition referred the comet to the glory of his own times. The fifth visit has been already ascribed to the fifth year of Justinian, which coincides with the five hundred and thirty-first of the Christian aera. 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 eleven hundred and six, is recorded by the chronicles of Europe and China; and in the first fervour of the Crusades, the Christians and the Mahometans might surmise, with equal reason, that it portended the destruction of the Infidels. The seventh phænomenon of one thousand six hundred and eighty was presented to the eyes 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 heavens was observed with exquisite skill by Flamstead and Cassini; and the mathematical science of Bernoulli, Newton, and Halley, investigated the laws of its revolutions. At the eighth period, in the year two thousand two hundred and fifty-five, their calculations may perhaps be verified by the astronomers of some future capital in the Siberian or American wilderness.

II. The near approach of a comet may injure or destroy the globe which we inhabit; but the changes on its surface have been hitherto produced by the action of volcanoes and earthquakes. The nature of the soil may indicate the countries most exposed to these formidable concussions, since they are caused by subterraneous fires, and such fires are kindled by the