Numa in imitation of the Greeks divided the year into twelve lunar months, according to the course of the moon, but as this mode of division did not correspond with the course of the sun, he ordained that an intercalary month should be added every other year. Julius Cæsar afterwards abolished this month, and with the assistance of Sosigĕnes, a skilful astronomer of Alexandria, in the year of Rome 707, arranged the year according to the course of the sun, commencing with the first of January, and assigned to each month the number of days which they still retain. This is the celebrated Julian or solar year which has been since maintained without any other alteration than that of the new style, introduced by pope Gregory, A. D. 1582, and adopted in England in 1752, when eleven days were dropped between the second and fourteenth of September. The months were divided into three parts, _kalends_, _nones_ and _ides_. They commenced with the _kalends_; the _nones_ occurred on the fifth, and the _ides_ on the thirteenth, except in March, May, July, and October, when they fell on the seventh and fifteenth. In marking the days of the month they went backwards: thus, January first was the first of the _kalends_ of January--December thirty-first was _pridie kalendas_, or the day next before the _kalends_ of January--the day before that, or the thirtieth of December, _tertio kalendas Januarii_, or the third day before the _kalends_ of January, and so on to the thirteenth, when came the ides of December. The day was either civil or natural; the civil day was from midnight to midnight; the natural day was from the rising to the setting of the sun. The use of clocks and watches was unknown to the Romans--nor was it till four hundred and forty-seven years after the building of the city, that the sun dial was introduced: about a century later, they first measured time by a water machine, which served by night, as well as by day. Their days were distinguished by the names of _festi_, _profesti_, and _intercisi_. The _festi_ were dedicated to religious worship, the _profesti_ were allotted to ordinary business, the days which served partly for one and partly for the other were called _intercisi_, or half holy days. The manner of reckoning by weeks was not introduced until late in the second century of the christian era: it was borrowed from the Egyptians, and the days were named after the planets: thus, Sunday from the Sun, Monday from the Moon, Tuesday from Mars, Wednesday from Mercury, Thursday from Jupiter, Friday from Venus, Saturday from Saturn. _A Table of the Kalends, Nones, and Ides._ Days of| Apr, June, | Jan, August, | March, May, | Month. | Sept, Nov. | December. | July, Oct. | February.