CYCLE of the Moon, called also the golden number, and the Metonic cycle, from its inventor Meton the Athenian, is a period of nineteen years, on the completion of which the new moons and full moons return on the same days of the month; so that on whatever days the new and full moons fall this year, nineteen years hence they will happen on the very same days of the month, though not at the same hour, as Meton and the fathers of the primitive church thought; and therefore, at the time of the council of Nice, when the method of finding the time for observing the feast of Easter was established, the numbers of the lunar cycle were inserted in the calendar, which, on account of their excellent use, were set in golden letters, and the year of the cycle called the golden number of that year.