YAWS

A disease in which eruptions form upon the skin, somewhat resembling a raspberry. See FramYEAR. A period of time determined by the revolution of the earth in its orbit, and embracing the four seasons. The year is either astronomical or civil. The astronomical year is determined by astronomical observations, and is of different kinds, according to the celestial body or the point of the heavens to which the earth's revolution is referred. When the earth's motion in its orbit is referred to an immoveable point in the heavens, to a fixed star, for example, the time of revolution is that which elapses from the instant at which the star, the sun, and the earth are in a straight line, till the earth returns again into the same straight line with the sun and the star. This interval is called the sidereal year. But when the earth's motion is referred to a point of the ecliptic, as one of the equinoctial points, or the tropics, the time of revolution is that in which the earth returns to that point, and is called the equinoctial, or tropical, or solar year. On account of the prece ion of the equinoxes {see Prece ion) the equinoctial and solstitial points, in reference to the fixed stars, have a retrograde motion on the ecliptic, in consequence of which the earth returns to one of these points in a shorter time than it returns to the same fixed star. The length of the sidereal year is 365-2563612 mean solar days; or 365 d. 6 h. 9 m." 9-6 sec. The length of the equinoctial or tropical year is 365-2422414 mean solar days, or 365 d. 5h. 48 m. 49-7 sec. (Baily's Tables, p. 16.) The difference is 19 minutes 19-9 seconds of mean solar time, being the time in which the earth describes in its orbit an arc of 50- 1", the annual prece ion of the equinoxes. See Earth. The earth's motion may also be reckoned by the time in which a revolution is completed with respect to the line of the apsides or the line of the nodes. In these cases the times of revolution may be called respectively the anomalistic year and the nodical year: the former term is sometimes met with. The civil year is the year of the calendar. As it is always supposed to begin with the beginning of a day, the civil year contains a whole number of days; and hence, in order that the seasons may always correspond with the same parts of the year, it is nece ary from time to time to vary the length of the year, or to intercalate a day when the fractional parts neglected have accumulated to a whole day. The ancient Egyptian year consisted invariably of 365 days, and hence was called a vague or erratic year, because the first day of the year in the course of 1460 years wandered as it were over all the seasons. The Julian year, which is frequently employed in chronological reckoning, consists of 3654 days. Julius Caesar ordered that the civil year should consist of 365 days for three succe ive years, and that the fourth year should contain 366 days. This practice of intercalating a day every fourth year has been adopted in all European countries, with the modification introduced by the Greg or i an calendar. The mean Julian year is longer than the true tropical year by 11 m. 10-3 sec, a difference which amounts to a whole day in about 120 years. The years which contain 365 days are called common years; those which contain 366 days are called leap years. See Leap Year. According to the regulations of the Greg or i an calendar the intercalations are omitted on years in which centuries end, excepting when the number of the year is divisible by 4, after leaving out the two zeros. Thus the years 1700, 1800, 1900, which would be leap years in the Julian calendar, are common years in the Greg or i an; but 1600 and 2000 are leap years in both calendars. (See Calendar.) The mean length of the Greg or i an year is 365 d. 5 h. 49 m. 12 sec, exceeding the true tropical year by 22-38 sec, which amounts to a whole day only in about 3866 years. The civil or legal year.in England, formerly commenced on the 25th of March, the day of the Annunciation, though the historical year began on the 1st of January, the day of the Circumcision, Between these two epochs it was usual to date the year both ways, as 1745-6, or I74|. By thr» act of parliament for the alteration of the style in 175], the beginning of the year was transferred to the 1 St of January. It is frequently nece ary to keep this circumstance in mind in referring to old dates. The fraction by which the tropical years exceed 365 [s. 1350]