Page:The American Cyclopædia (1879) Volume III.djvu/585

CALENDAR 579 most nations become fixed periods of 30 or 31 days. The length of the month in most civ- ilized nations has been copied from the Romans. No nation lias, however, followed the singular division which the Romans made of the month by means of three special days. The first day was called the calends, because it was an ancient custom of the pontiffs to call (Lat. calare) the people together on that day to apprise them of the festivals or days to be kept sacred during the month. The 13th or 15th day was called the ides; the nones were the 9th day before the ides, and the other days of the month were numbered from the next succeeding calends, nones, or ides. The day, for instance, which we call Feb. 19, they called the llth before the calends of March. The calendar shown in the engraving, found in Pompeii, indicates the number of days, the average length of the days and nights, and the festival or sacred days, in each month. The solar year is a natural period, formerly measured by the interval be- Calendar from Pompeii. tween two successive vernal equinoxes. If the civil year corresponds with the solar, the sea- sons of the year will always come at the same period. But in early times the Roman pon- tiffs regulated the length of the civil year so imperfectly, that in the days of Julius Casar the spring occurred in what the calendar called summer. Caasar, with the help of Sosigenes, reformed the calendar in 46 B. 0., and intro- duced our present arrangement of having three years of 365 days followed by one of 366, di- viding the year into months nearly as at pres- ent. The irregularity of alternation in the months of 30 and 31 days was introduced a few years after to gratify the vanity of Augus- tus, giving his month of August as many days as Julius Cffisar's month of July. The addi- tional day was given in leap year to February, by calling the 5th day before the calends of March a second 6th ; whence leap year is still called in the almanacs bissextile year (bii, twice, and sertus, sixth). This calendar of Julius Cassar is still used in the Russian empire, and was in use in all Europe till 1582. Its er- ror consists in giving the year a length of 365J days, which is about 1 1 minutes too much, an error which has now amounted to about 12 days. Pope Gregory XIII. ordered Oct. 5, 1582, to be called the 15th, and that all centu- rial years which are not multiples of 400 should not be made leap years; thus 1600 was a leap year, and 2000 will be the next that falls on a centenary year. This is called the Gre- gorian calendar, and is at present used in all Christian countries except Russia. It is a method of intercalation which reconciles with much accuracy the civil with the solar year. The latter consists of 365 d. 5 h. 48 rain. 49'62 sec. The Gregorian rule of omitting three leap years in every 400 years, reducing these to 146,097 days, gives to a civil year an average duration of 365 d. 5 h. 49 min. 12 sec., which exceeds the true solar year by 22'38 seconds, and amounts to the difference of a day only every 3,866 years. The most intricate matter in the calendar is the ecclesiastical rule gov- erning the movable feasts. The council of Nice ordained in the year 325 that Easter should be celebrated on the first Sunday after the full moon that occurs on or next after the day of the vernal equinox. The days of the week are denoted by the first seven letters of the alphabet, A being placed against Jan. 1. The dominical letter for the year is the letter which will then come against Sunday. The solar cycle is a period which restores the first day of the year to the same day of the week, by means of which we can find the dominical letter for any year, and therefore tell what day of the week it was or will be at any given date. The lunar cycle is a period which re- stores the new moon to the same day of the month. The golden number indicates the place of any given year in the lunar cycle, so that by means of it we can tell on what day of March the full moon falls, and thus find Easter day. The Gregorian calendar, civil and ecclesiastical, was soon adopted in the Catholic states.' In the Protestant states of Germany it was but partially adopted in 1700, and not wholly till 1774. The change from Julian to Gregorian reckoning was made by act of parliament in Great Britain in Septem- ber, 1752, the 3d of the month being called the 14th. The ancient Egyptians, Chaldeans, Per- sians, Syrians, Phoenicians, and Carthaginians, each began their year at the autumnal equi- nox (about Sept. 22). The Jews also began their civil year at that time, but in their eccle- siastical reckoning the year dated from the ver- nal equinox (about March 22). The beginning of the year among the Greeks until 432 years B. C., when Meton introduced the cycle called after him, was at the winter solstice (about Dec. 22), and afterward at the summer solstice (about June 22). The Greek astronomers had a solar year peculiar to themselves, to the months of which they gave the 12 signs of the