days from 1 Kan--the first day of the year given in Table
I--brings us to 2 Ezanab (the day we count from being excluded); 12 days
more bring us to 1 Oc, in the second column of our table; 17 days more to
5 Manik, in the third column; and 17 days more, to 9 Kan, in the fourth
column.

The number of the day required is readily ascertained by adding together
the number of the day counted from and the number of days to be counted,
casting out the thirteens when the sum exceeds this number (excepting
where the remainder is thirteen); thus: 1 + 14 - 13 = 2, the number of
the day Ezanab given above. So 1 + 14 + 12 - 13 - 13 = 1, the number of
the day Oc, second column, Table I; and 1 + 14 + 12 + 17 + 17 - 13 - 13 -
13 - 13 = 9, the number of the day Kan, fourth column. The reason for
this is so apparent that it is unnecessary to state it.

Suppose the day counted from is 11 Muluc of the eleventh month, and the
number of days to be counted (or the interval) is 19; by adding together
the numbers and casting out the thirteens the following result is
obtained: 11 + 19 - 13 - 13 = 4. Counting forward on the table 19 days
from 11 Muluc (the sixth number in the eleventh figure column), we reach
4 Lamat (the fourth day of the twelfth month). When the sum of the
numbers is a multiple of 13 the number obtained is 13, as there can be no
blanks, that is to say, no day without a number.

As the plates of the codices are usually divided into two or three
compartments by transverse lines, it is necessary to adopt some method of
referring to these in order to avoid the constant repetition of "upper,"
"middle," and "lower" division. On the plan proposed by Dr. Foerstemann,
in his late work on the Dresden Codex (Erlaeuterungen zur Mayahandschrift
der Koeniglichen oeffentlichen Bibliothek zu Dresden), these divisions are
designated by the letters _a_, _b_, and _c_; this plan will be adopted in
this paper. The letter _a_ joined to the number of a plate, therefore,
will signify that the division referred to is the upper one, as Plate
12_a_; the letter _b_ signifies the middle one where there are three
divisions or the lower one where there are but two; and the letter _c_
signifies the lowest or bottom division where there are three.

Where reference is made to the fac simile of the Dresden Codex,
Kingsborough's colored edition is always to be understood, except where
another is specially mentioned.

Running through Plates 36_c_ and 37_c_ is a