279 



history and chronology of their ancestors. These 

 manuscripts, which contain a great number of 

 dates, reckoning at the same time according to 

 the Christian era, and according to the civil and 

 ritual calendar of the natives, have been studied 

 with advantage by the learned Carlos de Siguen- 

 za, professor of mathematics at the university 

 of Mexico ; by the Milanese traveller, Boturini 

 Benaducei; by the Abbe Clavigero; and latterly 

 by Mr. Gama, whose astronomical labours I 

 have had occasion to mention in another work *. 

 Finally, in 1790, a stone of enormous bulk, 

 covered with characters evidently relative to the 

 Mexican calendar, the religious festivals, and 

 the days in which the Sun passes the zenith of 

 the city of Mexico, was discovered in the founda- 

 tions of the ancient teocalli. This served at the 

 same time to clear up some doubtful points, and 

 call the attention of some enlightened natives to 

 the Mexican calendar. 



I endeavoured, not only during myitay r 

 America, but after my return to Europe/to stur 

 carefully every thing that has been publish 

 on the division of time, and the mof of ir er ~ 

 calation among the Aztecks. I (/amine on / 

 the spot the celebrated stone founc^n the-Plaza / 

 Mayor, and represented in tly twei>y-thir<y 



* Essai polit. sur le Mexique, vol/ P- 24 * 1'fditi 

 in-8vo. / / 



