392 
examine more thoroughly the Mexican calendar. 
When his heirs shall have obtained the means of 
publishing his treatise on the Tolteck and Azteck 
chronology, it will be more easy to judge of the 
real number of the intercalary days. Gama’s 
astronomical labours, the exactness of which we 
have had an opportunity of verifying, ought to 
inspire great confidence ; and it is probable, that 
a scientific person, who has had the patience to 
calculate for the parallel of the ancient Teno- 
chtitlan, according to the tables of Mayer, a 
great number of eclipses of the Sun, connected 
with historical epochas, would not have lightly 
hazarded a new hypothesis, had he not been led 
to it by a careful comparison of dates, and by the 
study of hieroglyphical paintings. 
The intercalation of twenty-five days in a 
hundred and four years,” says Mr. La Place 
“ supposes a more exact duration of the tropical 
years than that of Hipparchus, and, what is very 
remarkable, almost equal to the year of the as- 
tronomers of Almamon. When we consider the 
difficulty of attaining so exact a determination, 
we are led to believe, that it is not the work of 
the Mexicans, and that it has reached'them from 
the Old Continent ; but from what people, and 
by what means, was it received ? Why, if it was 
= smitted to them from the north of Asia, is 
^ Expo, du du Monde, Sd ed., tom. 2, p. 818. 
