LET. XIV.

OF THE CALENDAR.

233

great men, who were the ornaments of thetimes in which they lived, had observed thatthe true equinox preceded the civil one, byabout a day in a hundred and thirty years. Andas the council of Nice, which was held in theyear 325, had fixed the vernal equinox to thetwenty-first of March, it was accordingly found,that from that time to the year 158a, when thenext reformation was effected, the error accumu-lated by this means, amounted to about tendays ; so that the vernal equinox was now foundto happen on the eleventh of March, instead ofthe twenty-first, as it ought to have done, hadthe Julian account agreed with the course of thefun.

This constant anticipation of the equinox,which in the course of more than a thousandyears, had become too obvious not to be no-ticed, was first represented to the councils ofConstance and Latran, by two cardinals, Ailliand Cufa, who shewed the cause of the error,and the means of correcting it. And in the year1474, Pope Sixtus IV. being convinced of thenecessity of a reformation, sent for Regiomon-tanus, a celebrated mathematician of that time,to Rome, and presented him to the archbifhop-rick of Ratifbone, in order to engage him in thisundertaking; but a premature death prevent-ing his assistance, the project was, for that time,suspended.

The