MAYAN NOMENCLATURE BY CHARLES P. BOWDITCH _Privately Printed_ CAMBRIDGE THE UNIVERSITY PRESS 1906 It has long been well known that the Mexican numeration is vigesimal, and, as far as I know, there is no proof that it was ever used in the calculation of long reaches of time. The Cakchiquel numeration is also vigesimal, and Brinton states (Maya Chronicles, p. 44) that the Maya numeration is also vigesimal, giving 20 units = one kal = 20 20 kal = one bak = 400 20 bak = one pic = 8000 20 pic = one calab = 160000, etc. But this Maya system is never used in connection with days. Wherever a long number of days is referred to, we find invariably the following system in use: 20 units = one of the second term 18 of the second term = one of the third term 20 of the third term = one of the fourth term 20 of the fourth term = one of the fifth term. And this system is, as far as we know, used for nothing else but for reckoning days. The only difference between the first system and the second is that in the first system twenty of the second term equal one of the third, while in the second system eighteen of the second equal one of the third. This difference is, of course, essential, and it seems most probable that the change was introduced in order to bring the third term as near the length of the year as possible, and to conform the day numeration to the number of days and months in the year. Professor Cyrus Thomas is unwilling to see in this anything more than the counters by which to count the days, and denies to it the name of a calendar; but as the system of day numeration is different from the usual system, and is used only for counting days, and as this system counts forward in almost every case in the inscriptions, and in a majority of cases in the Dresden Codex, from a fixed date, 4 Ahau 8 Cumhu, it seems impossible to see any difference between it and a calendar system.