HISTORY OF CHRONOLOGY. 763 



Ptolemaic system, was : 1. Saturn ; 2. Jupiter ; 3. Mars ; 4. Sun ; 

 5. Venus ; 6, Mercury ; 7. Moon. The Clialdeans called the twenty- 

 four hours of the day by the names of these planets in their order, and 

 named each day from the first hour of the day. Thus, first hour of 

 first day was Saturn ; last hour (or twenty-fourth) was Mars ; first 

 hour of next day was Sun, hence called Sunday ; first hour of next day 

 Moon, hence called Monday, etc. Our Saxon ancestors named the days 

 from their corresponding gods. Thus, what the Romans called Mars- 

 day, the Saxons called Tuisco-day (whence Tuesday), Tuisco being 

 their god of war as Mars was among the Romans, and so of the rest. 



The early Romans began the year with March, but in the time of 

 Caesar it began with January. The early Christian Church began it on 

 March 25th, and this was the beginning of the civil and ecclesiastical 

 year in England and her American colonies until 1752, when it was 

 changed by act of Parliament to January 1st. 



Cycles. To facilitate computation of time, to fix the recurrence of 

 moons and days, and to establish epochs as standpoints of chronology, 

 recourse was had to cycles, which we will now examine. The word 

 cycle is derived from a Greek word which signifies a circle here it 

 signifies a circle of time. The first and most important among them 

 was the Cycle of the Moon, the object of which was to accommodate 

 t^e computation of time by the moon to that of the sun. It was in- 

 i^ented about 430 b. c, by an Athenian named Meton, whence it was 

 called also the Metonic Cycle, and was used to fix the times of the 

 Grecian festivals, but fell into disuse with these festivals and was 

 afterward restored by the Council of Nice, a. d. 325, being best adapted 

 of all to fixing the time of Easter. 



This cycle, at the time of its invention, was deemed entirely correct, 

 and was so much superior to any other that had been attempted that 

 each year was written in letters of gold in the public marts of Greece, 

 from which cause it has ever since been known as the " golden number." 

 It was constructed as follows : It had been discovered that the lunar 

 year was eleven days shorter than the solar year ; so that, if a new 

 moon occurred upon any given day of any solar year, on the same day 

 of the next solar year the moon would be eleven days old, on the same 

 day of the second year twenty-two days old, etc. Examination showed 

 that the new moon would again occur upon the same day of the solar 

 year in the course of nineteen years. Hence the lunar cycle consists 

 of nineteen years. The other ancient cycles are unimportant for our 

 present purpose ; the other cycles that we shall consider are the in- 

 ventions of modern chronolosrers. 



Solar Cycle. Chronologers have affixed to the seven days of the 

 week the first seven letters of the alphabet, as follows : To January 1, 

 A ; January 2, B, etc., and whichever letter the first Sunday of the 

 year happens to fall upon is called the dominical or Sunday letter for 

 that year. The object of this cycle is to find (without reference to the 



