377 
admitted a far more simple mode of intercala- 
tion, than that of the Greeks and Romans before 
the introduction of the Merkidinus. If we cast 
our eyes upon the intercalations used among 
different nations, we see that some permit the 
hours to accumulate till they form a whole day, 
while others neglect the intercalation till the 
supplementary hours form a period equal to one 
of the great divisions of their year. The first 
mode of intercalation is that of the Julian year, 
the second is that of the ancient Persians, who 
added, every one hundred and twenty years, a 
whole month of thirty days to a year of twelve 
months, and so that the intercalary month ran 
through the whole year in 12 X 120 or fourteen 
hundred and forty years The Mexicans have 
evidently followed the system of the Persians ; 
they retained the vague year, till the supplemen- 
tary hours formed a half lunation, and they in- 
tercalated consequently thirteen days in every 
- ligature, or cycle of fifty-two years. Hence it 
followed, as we have already observed, that 
each ligature contained or one thousand four 
hundred and sixty- one small periods of thirteen 
days. The Mexican year began at the commence 
ment of the xiuhmolpilli, on the day which corres- 
ponds to the 9th of January of the Gregorian 
calendar. The fifth, ninth, and thirteenth years 
Ideler, TIist. Uiiters., s. 379. 
