tET. I. OF ASTRONOMY. If

very rare and uncommon. And what will appearstill more singular is, that we owe them entirelyto the gross ignorance and superstition of thetimes in which they were made. The phæno-mena of eclipses, and particularly those of thesun, were the occasion of general consternationand terror; and from the records they have leftus of these alarming appearances, we are ableto find the times in which they happened.

If the writings of an historian were entirelylost, and we could only obtain a certain vaguerelation of facts, without dates, but accompaniedwith an account of some remarkable eclipse;the astronomer, by his knowledge of the ce-lestial motions, would be soon able to find theprecise time in which they must have happened.It was by this means, that the celebrated Dr.Halley determined the very day and hour ofJulius Cæsar’s landing in Great-Britain, merelyfrom the circumstances of his relation. And tothe same cause it is owing, that the chronologyof the Chinese is much more authentic thanthat of most other nations. Their attachmentto ancient customs, and the superstition whichis so intimately blended with the administrationof their public affairs, has led them to preserveaccounts of eclipses that prove the existence oftheir empire for near 4000 years past.

But an advantage still more interesting andimportant, is the assistance which this science

affords