496 BUREAU OF AMERICAN ETHNOLOGY [bull. 28 



by a glypli which contains a certain day (Imix) as its principal part, 

 but as a superior affix a figure which expresses a tieing together. I 

 have hazarded this conjecture in the Zeitschrift fiir Ethnologie, 1891, 

 pages 152 and 153. The selection of Imix for this sign must there- 

 fore have occurred at a time when Imix was accounted the first of the 

 20 days. 



The creation of time periods did not cease here. The movement of 

 the most conspicuous planet, Venus, was also taken into consideration, 

 and it was found that its apparent revolution embraced a period of 

 584 days. This had now to be harmonized with the newly discovered 

 solar year, which could be easily done: 5X584=8X365=2,920. We 

 find this latter number clearly indicated as the basis of the calcula- 

 lations on page 24, as well as on pages 46 to 50 of the Dresden codex. 

 Then the Aztecs after every 8 solar years celebrated the greatest 

 s])lendor of Venus, when Venus " smokes " (see Anales del Museo 

 Nacional de Mexico, volume 2, 1882, page 342). As we saw above, 

 the Mayas proceeded from 4,680 to its triple, 14,040, in order to obtain 

 greater divisibility ; so, too, they advanced from 2,920 to its triple, 

 8,760, which is divisible by 3, 6, and 12. This is the ahau of 24 years 

 of 365 days each, so often mentioned, virtually the principal period 

 in Maya history. Here we are indebted to Cyrus Thomas, who, by his 

 full investigation of the subject, laid the foundation for further re- 

 search (see A Study of the Manuscript Troano, pages 28 to 58). 



Both the period of 2,920 and that of 8,760 days still had a defect. 

 They did not harmonize with the tonalamatl of 260 days. The double 

 katun of 2X18,980=37,960 days, or 104 solar years, was therefore 

 introduced, as we see it especially in the Dresden manuscript, pages 

 46 to 50, where three such i:>eriods are computed, in each of which 260, 

 365, and 584 are factors. 



The next task was to find a period in which both the ahau and the 

 katun, as well as the revolution of Venus, that is, 8,760, 18,980, and 

 584, are contained. Accordingly, the triple of the period just men- 

 tioned, the double katun, was employed, which resulted in the ahau 

 katun of 113,880 days^6 katuns=13 ahaus=195 Venus years=312 

 solar years:^438 tonalamatls. 



But the utmost perfection was attained in the period of 12 ahau 

 katuns= 1,366,560 days, divisible not merely by tonalamatl=260, solar 

 year=365, Venus year=584, ahau -=8,760, and katun= 18,980 days, 

 but also by 9, all important in Maya mythology, and hence b}^ the old 

 jesir of 360 days. This important period with the figures 



9 

 9 



16 

 

 



