MANUSCRIPTS OF MEXICO SPINDEN" 447 



his month, Toxcatl. Later it seems that the beginning of the civil 

 year was pushed forward several months. 



Unfortunatel}^ no method was found to designate the different 

 52-year cycles, and when errors are made, generally by wrongly 

 reading the numerical coefficients of the days Knife, House, Rabbit, 

 and Reed (Tecpatl, Calli, Tochtli, and Acatl), which name the 

 years, the effect is nearly always to produce the interpolation of 

 entire cycles into the chronology. Fortunately, there are several 

 unbroken year counts for Aztec history which depart from the 

 year 1 Knife, 11G8, and it is possible to demonstrate the errors in 

 interpolations made by Ixtlilxochitl, Chimalpahin, and the anony- 

 mous author of the Annals of Cuauhtitlan. Actually, I do not 

 think the custom of keeping annals prevailed among the tribes of 

 the Mexican highlands until bookmaking was introduced by bands 

 of Toltec warriors returning from Yucatan in the fourteenth cen- 

 tury. An earlier use of writing in eastern and southern Mexico is 

 indicated by the inscriptional record, but this also followed the 

 model which Quetzalcoatl had perfected, 



ASTRONOMICAL EVIDENCE IN CHRONOLOGY 



Ludendorff in eight papers on Maya astronomy has demonstrated 

 the correctness of the correlation of Maya and European dates 

 which I had the honor to present and which for a time was subject 

 to intense controversy. He has also demonstrated the marvelous 

 accuracy of observations in connection with nearly all the planets. 

 Part of this astronomy was carried over by Quetzalcoatl into the 

 ceremonialism of non-INIaya peoples. In the codices of southern 

 Mexico there are numerous representations of the Venus staff and of 

 human sacrifices connected with the time of the inferior conjunction 

 of the planet Venus and the Sun. It is possible to convert a Mexican 

 date into a Maya one or at least find the places at intervals of 52 

 years where such a date must fall in the precise Maya system. 



The most conspicuous representations of Venus ceremonies are 

 in connection with a day 1 Crocodile in a year 1 Reed. This date 

 is recorded 21 times in the Vienna codex and it runs on the cover 

 of the Codox Zouche as well as in the text in association with well- 

 Iniown objects of the Venus cult. Converting this recurrent Mexi- 

 can date into Maya and then European equivalents, we find the 

 most probable position in relation to Venus to be April 5, 14G7, 

 Gregorian Calendar. Here it coincides with the last visibility of the 

 planet as evening star before an inferior conjunction with the sun 

 on about April 9, while a first visibility of the planet as morning 

 star falls on April 13. This agrees very closely (the discrepancy 



