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departed. This is called the solar year; and confifts, according to our account, of 365 days, five hours, and forty-nine minutes. This is properly the tropical or natural year. But that space of time . in which the sun having departed from any fixed star, returns to the same again, is called the sidereal year, and contains 365 days, fix hours, and ten minutes.
A lunar year is that space of time, in which the moon perforins twelve complete revolutions round the earth, called Lunations. This year contains 354 days, eight hours, forty-eight minutes, and thirty-eight seconds.
Both the folar and lunar years above described, are termed astronomical, as depending on the prin-1 ciples and observations of Astronomy.
A civil year is the legal year, or that which each nation or government has appointed for common use. This is made to consist of a certain number of whole days, without any odd hours or ininutes, to render the computation of time inore easy. It is distinguished into common and bilfextile. The common year consists of 365 days; and the biflextile, or leap-year, which is every fourth, of 366.
The addition of a day to every fourth year is to make the civil year keep pace with the natural one ; for the fix hours, or thereabouts, by which the
latter exceeds the former, in four years make a whole day; and therefore every leap-year the month of February has 29 days, which in the common year has but 28.
The intercalary, or additional day to every fourth year, was first appointed by Julius Cæsar, who ordered it to be inserted after the 24th of February, which was the fixth of the calends of March, according to the Roman way of reckoning. This year, therefore, they reckoned the 24th of February twice over, having, as they expressed it, bis fexto calendas Martias ; and hence the year had the name of biffextile. But amongst us, this intercalation is : not made by telling the 24th of February twice, but by adding a day to the end of that month.
It is called leap-year, because in the common years any fixed day of the month changes successively, the day of the week; but in the biffextile it skips or leaps over one day. For instance, suppose the ist of May in a common year falls on Tuesday, if the next be a common: year it will be on Wednesday ; but if it be a leap-year, the adding of a day will cause it to skip over Wednesday, and fall on Thursday
In order to know whether any particular year be leap-year or not, divide it by four, and the remainder, if there be any, shews how many years
have elapsed since leap-year; and, if there be none, then it is leap year. Or you may omit the hundreds and thousands, and divide only the units and tens by four, and the result will be the fame. For example ;' divide 1792 by' 4, the remainder is o; of divide only 92 by 4, the remainder is likewife o'; confequently 1792 is leap-year. Divide 1793 by 4, the remainder is i; or divide only 93 by 4, the remainder is likewise 1 ; consequently 1793 is the firft year'after leap-year.
The lunar year, as instituted by Romulus, the founder of Rome, consisted but of ten months ; but as this was short of the sun's period by two months, these were afterwards ådưed by his fuck cestor, Numa Pompilius; 'ånd were called January and February. By these means the Roman year consisted of twelve months. But the months of this year being only lunar months, of 29 days each, this civil liinar year consisted but of 354 days. The fun, however, in revolving once through the ecliptic, was found, in process of time, to take up 365 days, or eleven days more than, the lunar year, Thele were added to it by Julius Casar
, and on that account it was called the Julian year.
The Gregoriin year is a correction of the Julian made by Pope Gregory XIII. and that yvith very good reason ; for the Julian year of 365 days and
fix hours exceeding the true solar year by eleven minutes, this excess in 131 years amounts to a whole day. The council of Nice, in the year of Christ 325, appointed the celebration of Easter to be always on the first Sunday after the full moon that came next after the vernal equinox, which was then on the 21st of March. Pope Gregory, however, in the year of our Lord 1582, obServed that the above-mentioned fault of the Julian year had thrown the equinoxes ten days more backward, than they were at the time of the said council, so that the vernal equinox was then on the lith of March. This occasioned great irregularity with refpe& to the time of celebrating Easter, and con, sequently all other Moveable Feasts. The Pope, therefore, to correct this error, ordered ten days to be suppressed in the month of October 1582, that to the equinox might be reduced to the 21st of March, on which day it fell at the time of the Nicene council. And that this variation might not' happen again, it was further ordained, that every hundredth year, which in the Julian account was a leap-year, should in this be only a common year, and consist but of 365 days ; but as that was too much, every four hundredth year was to remain a leap-year or biflextile.
This reformation of the calendar is called the Gregorian account, or New Stile; and according to this stile was the calendar rectified in England in 1752, by throwing out eleven days in the month of September, as from the council of Nice to that year, 1427 years had elapsed; and, besides, the beginning of the civil year was fixed to the first day of January
This emendation, adjusts the year and seasons pretty near the truth, and has been received not only in all popish countries, but in Holland, Denmark, Sweden, England, and the Protestant states: of Germany.
CH A P. LIV.
FORMS OF CIVIL YEARS.
THERE have been, and still are, various forms
of civil years, in different nations, four of which I shall take some notice of.
1. The ancient Roman year of Romulus consistedof ten months, namely, Martius of 31 days, Aprilis of 30, Maius of 31, Junius of 30, Quintilis of 31,