150 . ,?¥OYASTRONOMY. hy 
Calendar of the Ancient Greeks. 
73. The ancient Greeks assumed a lunar year of 354, later of 360 days, 
or 12 months of 80 days each, which they then sought to. accommo- 
date .o the true solar year by intercalations. In honor of the Olympic 
games, the beginning of the year was placed at the first new moon after the 
summer solstice. Nevertheless, this did not always fall in July, as the 
Olympiads themselves consisted sometimes of 49, sometimes of 50 months. 
This Greek calendar was as complicated as the Macedono-Grecian calendar, 
introduced at a later period by Philip of Macedon, which commenced its 
year at the autumnal equinox, and which was employed for the names of 
the months, but not in their order, by the Greeks, Phcenicians, Babylonians, 
Medes, &c. The months of 30 days were called full; those of 29 days 
deficient ; and each of these fell into three decades. By the gradual intro- 
duction of the Roman calendar among the nations subjected to that. power, 
the Grecian fell into disuse. 
Calendar of the Romans; the Julian Calendar. 
74. The Roman calendar, improved by Numa Pompilius, was based on a 
lunar year, having one more day than a solar year. The first day of every 
month (the new moon) was called the calend, and besides this, two others 
were distinguished, the 18th before every new moon the Ide, and the 9th 
before the Ide the None. According to the reckoning of Numa, four months 
(Martius, Maius, Quintilis, and October) contained 31 days, and the rest 
29 days, except February with 28, and the Macedonian month which was 
intercalated every two years with 22-23. There were therefore nones of 
seven and of nine days; with later arrangements the Ides also happened 
differently. The intermediate days were counted backwards from the Ides 
of the same, or the calends of the next month, as also from the nones of the 
same month. The Romans had besides periods of nine days, called nun- 
dine, which were indicated by the letters A to I. The dies fasti and 
nefasti were days of good and bad omen. Through the irregularity of dis- 
tribution, and the then low state of astronomical science, it came to pass 
that about 46 years B.c. the Roman calendar varied about 59 days from the 
true day (that is, from the true place of the sun in the ecliptic). This 
induced Julius Cesar, by the advice of the Alexandrian mathematician, 
Sosigenes, to adopt the solar year of 365 days, 6 hours, and so arrange the 
calendar that every year divisible without remainder by 4, should consist 
of 366 days, the rest consisting of 865. With respect to the subdivisions 
of the calendar, Julius Cesar retained the old terms of calends, nones, and 
ides. This calendar is called the Julian. 
150 
