DIVISIONS OF TIME 259 



increases the duration of his stay above the horizon until 

 the longest day is reached — the summer solstice (June 

 2ist). Julius Caesar took January ist for New Year's Day 

 \as being the first day of a month nearest to the winter 

 solstice. The ancient Greeks regarded the beginning of 

 September as " New Year." 



Were mankind content with the measure of time by the 

 completion of a cycle of revolution of the earth around the 

 sun — that is the year— and by the revolution of the earth 

 on its own axis — that is the day or day-night {w^jBriiiipov) 

 of the Greeks — the notation of time and of seasons 

 would be comparatively simple. No one seems to know 

 why or when the day was first divided into twenty-four 

 hours, nor why sixty minutes were taken in the hour and 

 sixty seconds in the minute. The ancient astronomers of 

 Egypt and China, and their beliefs in mystical numbers, 

 have to do with the first choosing of these intervals in un- 

 recorded ages of antiquity (as much as 2000 or 3000 B.C.). 

 The seven days of the week correspond to the five 

 planets known to the ancients, with the addition of the 

 sun and the moon. But the Greeks made three weeks 

 of ten days each in a month. The true year — the exact 

 period of a complete revolution of the earth around the 

 sun — is 365 days 5 hours 18 minutes and 46 seconds. 

 It was measured with a fair amount of accuracy by very 

 ancient races of men, who fixed the position of the rising 

 sun at the longest day by erecting big stones, one close 

 at hand and one .^t a distance, so as to give a line 

 pointing exactly to the rising spot of the sun on the 

 horizon, as at Stonehenge. They recorded the number of 

 days which elapsed before the longest day again appeared, 

 and they marked also the division of that period by the 

 two events of equally long sunlight and darkness — the 

 spring and the autumn " equinox." It is obvious that if 

 they took 365 days roughly as the period of revolution 



