The Gregorian year, or, as it is vulgar ly called, the new style, was immediately adopted in Spain, Portugal, and part of Italy. It was introduced into France in October of the same year, the tenth of which month was, by an ordinance of Henry Ill. reckoned the twentieth day. In Germany it was adopted by the Catho lic states in 1583, but the Protestant states adhered to the old calendar until the year 1700. Denmark also adopted it about this period, and Sweden in 1753. It was not used in England before 1752, when, by act of Parliament, the was changed, and the third of Sep tember was reckoned the fourteenth, the difference having by this time increased to eleven days. Russia is the only coun try in Europe in which the old mode of reckoning is still in use.
The want of some specific standard, which could be regarded as common to all nations, has occasioned great diversity in different countries in fixing the be ginning of the year. The Chaldmans and Egyptians reckoned their years from the autumnal equinox. The Jews also reck oned their civil year from this period, but began their ecclesiastical year in the spring. Gemschid, the King of Persia, ordered the year in that country to com mence at the vernal equinox. In Sweden the year formerly commenced at the winter solstice. The Greeks used differ ent methods, some of the states begin ning the year at the vernal, others at the autumnal equinox, and some at the sum mer solstice. The Roman year at one time began in March, but afterwards was made to commence in January. The new year's clay of the Church of Rome is fix ed on the Sunday nearest the full moon of the vernal equinox. In England, the year began in March until A. D. 1752, when the act of Parliament which altered the style ordained it to commence on the first of January.
Having thus given a short account of the lunar and solar years which have been mostly in use, and an acquaintance with which is of most consequence in chronology, it will be proper just to no tice some combinations of years which are mentioned in ancient history, and there fore proper to be known.
Lustra. The Romans sometimes reck oned by lustra, a period of five years, which derived its name from a census instituted by Servius Tullius, which was to be paid by the Roman people every fifth year.
The Olympiads were, however, the most remarkable of these combinations. They consisted of four Grecian years, and derived their names from the pub lic games celebrated every fourth year at Olympia, in I'eloponnesus. These games were instituted in honour of Ju piter, but at what time, or by whom, is not known. After they had been ne glected and discontinued for some time, they were restored by Iphitus, King of Elis, in the year B. C. 776; and it is from
this date that the Olympiads are reckon ed in chronology.
Cycles are fixed intervals of time, com posed of the successive revolutions of a certain number of years. The lustra and the olympiads may perhaps be included under this name, but the term is more commonly appropriated to larger inter vals, connected with the periodical re turn of Certain circumstances and appear ances. The great use made of cycles in chronology requires that they be parti cularly noticed.
From the defective nature of the Greek calendar, the olympic year, as it has been called, was subject to consider able variation ; and, from the retroces sion of the months which it occasioned, producing a gradual change of the sea. sons when the games were to be cele brated, led to much inconvenience. Cleostrates, a mathematician of Tene. dos, endeavoured to give it a more per fect form, by inventing a cycle of eight years: this, however, being computed by lunar years, still left the calendar subject to great inaccuracies. To rectify these, Meton, a mathematician of great celebri ty, invented— The Lunar Cycle, a period of nineteen solar years, at the end of which interval the sun and moon return to very nearly the same part of the heavens. This im provement was at the time received with universal approbation ; but not being perfectly accurate, was afterwards cor rected by Eudoxus, and subsequently by Calippus, whose improvements modern astronomers have adopted.
The use of this cycle was discontinued when the games, for the regulation of which it was composed, ceased to be celebrated. The Council of Nice, how ever, wishing to establish some method for adjusting the new and full moons to the course of the sun, with the view of determining the time of Easter, adopted it as the best adapted to answer the pur pose: and from its great utility, they caused the numbers of it to be writ ten on the calendar in golden letters, which has obtained for it the name of the golden number. The golden number for any year is found as follows :—The first year of the christian zra corresponds to the second of this cycle ; if then to a given year of this mra one be added, and the sum be divided by 19, the quotient will denote the number of cycles which have revolved since the commencement of the Christian era, and the remainder will be the golden number for the given year. e. g. If the golden number of the present year (1808) be required, one be ing added, the sum will be 1809; this be ing divided by 19, will give 95 for the quotient, and 4 for the remainder, or golden number sought.