LET. XIV. OF THE CALENDAR. 2ZZ

from the month of October, of the year thencurrent, and the equinox brought back to thetwenty first of March, as it had been fettled by-the Nicene council. And, that a like variationmight not happen in future, it was ordered,that instead of making every hundredth year abissextile, as was the cafe in the former method,every four hundredth year only should be con-sidered as a bissextile, and the rest be reckonedas common years.

The length of the solar year, and the time ofthe vernal equinox, were by this means veryaccurately settled; for as a day was gained, bythe former method of reckoning, in every hun-dred and thirty years, this was nearly equiva-lent to a gain of three days in every four hun-dred years; and consequently, by making theyears 1700, 1800, and 1900, to be commonyears instead of Leap-years, as they would other-wise have been, the error arising from the oddtime would be properly corrected. But thiswas a part of the subject that was easily accom-plished ; the great difficulty consisted in makingthe lunar year agree with the solar one, and infettling the true time for the observance ofEaster, and other moveable feasts, which hadhitherto been subject to no regular rule.

It was ordered by the council of Nice, thatEaster should be celebrated upon the first Sun-day, after the first full moon, next following the

vernal