Compendium of Chronology - Containing the Most Important Dates of General History, Political, Ecclesiastical, and Literary, From the Creation of the World to the End of the Year 1854 #271665

Cycles, from cyclos, a circle, is a designation of a recurring period of time. The three most considerable cycles are, the solar, the lunar, and the Roman indiction. The Solar Cycle is a revolution of 28 years. This includes all the possible combinations of the days of the week with the days of the month. If there were no bissextile, or leap year, it is evident that, after seven years had elapsed, the same days of the week would again answer to the same days of the month. For in stance, if the dominical letter for 1808 be B, it would become so again in seven years, which would confine the solar cycle to that period. But as every fourth year is bissextile, this consequently deranges by one day this successive return of the days of the week to answer to the days of the month. This adaptation will not, therefore, take place till after four times seven years. In order to find the solar cycle, add 9 to the given year, and divide the sum by 28, the remainder will Show the year of the solar cycle. If nothing remains, it will be the 28th year of the cycle.