CLIMATIC CHANGES AND MAYA HISTORY. 227 



The paramount difficulty in Maya history is the correlation of the ancient and recent 

 Maya calendars with one another and with the European system of chronology. The 

 complexity of the matter may be illustrated by the fact that the date of Stela 9 at 

 Copan is interpreted by Seler as 1255 b. c, by Bowditch as 34 a. d., and by Morley as 

 288 A. D. The trend of recent opinion seems to be that Seler's date is much too early, 

 but the entire matter is still an open question. The ancient Mayas who built the ruins 

 and the modern ones who wrote the chronicles just after the Spanish invasion used the 

 same highly complex calendar, but with slightly different adjustments and varying degrees 

 of completeness. The major units of tliis calendar were the "tun," having a length of 

 360 days; the "katun," consisting of 20 tuns; and the cj^cle, composed of 20 "katuns," 

 or approximately 398 years. According to the ancient method every date consisted of 5 

 numbers, indicating the cycle, katun, tun, month, and day. In later times this cumbersome 

 method was abandoned and seems to have passed out of use several centuries before the 

 coming of Europeans. An abbreviated system was in use at the time of the Spanish con- 

 quest and the great problem of Maya chronology is to correlate this with the ancient system 

 and with the European chronology. One of the peculiarities of both ancient and later 

 calendars was that each katun or 20-year period began with a day called "Aliau." The 

 Ahau was a sequence of 13 days, and different days were designated as 1 Ahau, 2 Ahau, etc. 

 It so happened that the Ahau days with which successive katuns began fell in the following 

 sequence: 13, 11, 9, 7, 5, 3, 1, 12, 10, 8, 6, 4, 2. Among the later Mayas the dates were 

 simply indicated by giving the number of the day Ahau with which the given katun 

 began. Hence, while the old method fixed the date for all time, provided the year 1 

 were definitely known, the later method only fixed its relative position in the period of 

 260 years making up the 13 katuns of a single series of katuns beginning with the 13 

 Ahau days. It is as if we were to abandon the use of the numbers indicating centuries 

 in our era and to write only the last two figures of our dates. If we did this we should 

 know that the years '20 and '50 were 30 years apart, provided that they fell in the same 

 century, but if we had two such dates and did not know their centuries one might be 1220 

 and the other 1550. Thus in using the later Maya calendar great care must be exer- 

 cised in order not to confuse the various 260-year periods, for otherwise the chronology 

 becomes utterly unreliable and the time of any event may be displaced by 260 years or by 

 some multiple of 260. 



Maya chronology, as Spinden expresses it, "rests upon a tripod foundation, one leg 

 being the chronicles preserved after the coming of the Spaniards, another leg being the 

 inscribed dates, and the third being the natural order of art and architecture. The earliest 

 period is strong through the practical coincidence of the inscribed dates and the natural 

 order of the art. The latest part of the history is equally certain on account of the fullness 

 of the traditions. The intermediate period is the only one which as yet has been incapable 

 of strong reinforcement." The traditional history of the Mayas was recorded in the Maya 

 language, but in Spanish letters not long after the Conquest. It is fairly full for later times, 

 but of course becomes less and less dependable as we go farther into the past. Its dates are 

 given in the abbreviated later style, but as this was still used at the coming of the Spaniards 

 the dates can of course easily be determined in the European calendar. Farther back the 

 danger of mistakes greatly increases, but for five or six centuries it does not become serious, 

 for the errors must amount to 260 years, and so are easily avoided. Back of about 900 

 A. D., however, the traditions become scanty and confused and the possibility of errors 

 increases enormously. The traditional history is connected with that of the dated monu- 

 ments only most vaguely. For example, it refers to the "discovery" of Chichen Itza and 

 to its abandonment and reoccupation, but at Chichen Itza only a single date has been found, 

 upon a lintel. This hntel does not seem to be in its original position, but to have been 

 rebuilt into a new structure after the old one had fallen to ruins. 



