And what, besides, would all these systems come to, had the figures and the names of the zodiacal constellations been given to them without any relation to the course of the sun; as their inequality, the extension of several of them beyond the zodiac, and their manifest connection with the neighbouring constellations, seem to demonstrate was the case[240]. What would still happen, if, as Macrobius expressly says[241], each sign must have been an emblem of the sun, considered in some one of its effects or of its general phenomena, and without reference to the months when it passes, whether into the sign, or to its opposite? Lastly, What if the names had been given in an abstract manner to the divisions of space or time, as they are now given by astronomers to what they call the signs, and had not been applied to the constellations or groups of stars, but at a period determined by chance, so that nothing could be concluded from their signification[242]? In these suggestions there is, without doubt, enough to give an ingenuous mind a distaste for seeking to find in astronomy proofs of the antiquity of the nations. But were these alleged proofs as certain as they are vague and destitute of any satisfactory result, what could be concluded from them against the great catastrophe, which has left monuments amply demonstrative in other respects of its existence? All that can be admitted in this matter is, what some moderns have thought, that astronomy was among the number of the sciences preserved by those whom this catastrophe dispersed. _Exaggerations relative to the Antiquity of certain Mining Operations._ The antiquity of certain mining operations has also been much exaggerated. A very late writer has imagined, that the mines of the island of Elba, judging from the rubbish carried out of them, must have been wrought for more than 40,000 years; but another author, who has also examined this rubbish with attention, has reduced the period in question to a little more than 5000 years,[243] and this even on the supposition that the ancients did not extract annually more than a fourth part of the quantity of ore now wrought. But what reason could there be to suppose that the Romans, for example, who consumed so much iron in their armies, derived so little advantage from these mines? Moreover, if these mines had been wrought for even 4000 years only, how should iron have been so little known in the times of remote antiquity? _General Conclusion relative to the Period of the last Revolution._