THE MAYAN CIVILIZATION 



111 



double entry, first by numbers, second by named days. 

 The numbers add up to 1 1 ,958 while the total difference 

 between the named days is 1 1 ,959. The purpose appears 

 to have been to approximate 1 1,960. This last number 



of days contains the tzolkiii an even number of times and 

 would thus form a re-entering series since it would al- 



Flg. 41. Representations of the Moon: a, sun and moon hieroglyphs; 

 b, moon from a "celestial band"; c, moon hieroglyph used for 20 in 

 codict 



Fig. 42. The Last Glyph of the Supplementary Scries: a, moon 

 glyph; combined with the numeral 9 or 10 to indicate a 29 or a 30 

 day lunar month. 



ways begin with the same day. Now it is a remarkable 

 fact that the total obtained by modern astronomers for 

 405 lunar revolutions is 1 1,959.888 days or only 0.1 12 of 

 a day less than 11,960. Therefore, this re-entering series 

 of the Mayan astronomers can be used nine times be- 

 fore an error amounting to one whole day has accumu- 

 lated. In other words, the lunar calendar was brought 

 into a fixed relation with the day count with an error of 

 one day in 300 years. 



On the monuments a more or less orderly group of 

 hieroglyphs following the Initial Series has been called 



