251 



in diameter, four centimetres high, and three 

 millimetres thick. We can scarcely conceive 

 how a vitreous and fragile substance could be re- 

 duced to the state of so thin a plate. Besides, 

 tecpatl differs from obsidian, a substance which 

 the Mexicans called iztli ; jade, hornstone, and 

 flint being confounded under the denomination 

 of tecpatl. 



The sign ollin or ollin-tonatiuh, presides, in 

 the beginning of the cycle of 52 years, over the 

 seventeenth day of the first month. The expla- 

 nation of this sign has greatly embarrassed the 

 Spanish monks, who, without the slightest ele- 

 mentary notions of astronomy, attempted to ex- 

 plain the Mexican calendar. The Indian authors 

 translate ollin by motions of the Sun. When 

 they find the number nahui added, they render 

 nahui ollin by the words Sim (tonatiuh) in his 

 Jour motions ; sometimes (Plate 37) like two 

 ribands intertwined, or rather like two portions 

 of curves, which cross each other, and which 

 have three perceptible inflections at their sum- 

 mits ; sometimes (Plate 23) like the solar disk 

 surrounded with four squares, which contain the 

 hieroglyphics of the numbers one fee) and four 

 (nahui) ; at other times like three prints of feet. 

 The four squares allude, as we shall soon explain, 

 to the famous tradition of the four ages, or four 

 destructions of the world, which took place on 

 the days 4 tyger, nahui ocelotl ; 4 wind, nahui 



