Page:Popular Science Monthly Volume 27.djvu/564

546 periods of sixty years we have to omit two years, one in the first cycle, and the other in the third; but in thirty cycles we have to omit $$0\cdot 7\ \text{year}\times 30= 21\ \text{years}$$, while the preceding correction has omitted only twenty years; so a new suppression of a year has to be performed in each series of thirty cycles.

The Hindoos also employed ages in the computation of time, and these, too, divided into periods of different durations. The present age is the kali yuga, or the age of iron; 4,985 years of it have already passed, but its total duration is supposed to be 432,000 years. The succession of the ages, counting back, is given as follows:

Fourth age—Kali yuga, age of iron, or of woe (the present age), to be of 432,000 years. Third age—Dvapara yuga, 864,000 years. Second age—Treta yuga, or age of silver, 1,296,000 years. First age—Krita yuga, age of gold, or of innocence, 1,728,000 years.

These four ages form the maha yuga, or great age, of 4,320,000 years. The length of a patriarchate is seventy-one maha yugas, or 306,720,000 years, to which is added a twilight period of 1,728,000 years, making in all 308,448,000 years. Fourteen of these patriarchates, augmented by a dawn of 1,728,000 years, gives 4,320,000,000 years, which form a kalpa, or the æon of the Hindoo chronology.

A kalpa is only a day in the life of Brahma, whose nights are also of the same duration. Now, Brahma lives a hundred years of three hundred and sixty days and three hundred and sixty nights. The present epoch is the kali yuga of the twenty-seventh grand age of the seventh patriarchate of the first æon of the second half of the life of Brahma, who is now in his 155,521,972,848,985th spring. Yet the whole life of Brahma is only a little longer than a single wink of Siva's eye!

The Greeks employed first two years of 12 months each consisting of 30 days, and a third year of 13 months, giving an average of 370 days to the year; then the cycle of 19 lunar years, with seven months intercalated in each cycle to obtain 19 solar years. The months were of 29 and 30 days, and the time was calculated by Olympiads, of four years each. Afterward, Calippus introduced the cycle of Méton, 433 years shorter than the 19 solar years, in consequence of the suppression of a day every 76 years. The era of the Olympiads goes back to 776, at which time Corœbus obtained the prize in the race, from and after which date the names of the victors were inscribed on the official registers.

The ancient Egyptians reckoned at first 12 months of 30 days, or 360 days; but they afterward added five supplementary days. The years were counted from the accession of the kings; and the canon of Ptolemy is a chronological table giving the changes of the reigns. The same form of year was formerly in use among the Persians, with the difference that they added the five supplementary days to the eighth month instead of to the twelfth. Their months had particular