bles of Antiquity which are blended and confounded with Hiſtory, and fix an uncertain Chronology. 'Tis true, that there is no Family, City or Nation, but endeavours to remove its Original as far backward as poſſible, Beſides, the firſt Hiſtorians were the moſt negligent in ſetting down the Æra's; Books, were infinitely leſs common than they are at this Time, and conſequently Authors being not ſo obnoxious to Cenſure, they therefore impos'd upon the World with greater Impunity; and as 'tis evident that theſe have related a great Number of fictitious Particulars, 'tis probable enough that they alſo gave us ſeveral falſe Æra's.
It appear'd in general to Sir Iſaac, that the World was five hundred Years younger than Chronologers declare it to be. He grounds his Opinion on the ordinary Courſe of Nature, and on the Obſervations which Aſtronomers have made.
By the Courſe of Nature we here underſtand the Time that every Gene-
