, years,
the series will appear to be ascending toward the left, with the
difference 4 months and 11 days, as shown by addition, thus:

Y. M. D.
4 11 Numbers over the fourth column.
4 11
---------------
9 2 Numbers over the third column.
4 11
---------------
13 13 Numbers over the second column.

Doubling the difference and adding we obtain the numbers over the first
column:

Y. M. D.
13 13
9 2
---------------
1 4 15

What adds to the difficulty is the fact that if the columns are taken in
reverse order the interval between the corresponding days is 4 months and
11 days; that is to say, counting from 13 Ix, first day of the fourth
column, to 13 Chicchan, first day of the third column, we find the
interval to be exactly 4 months and 11 days; and the same rule holds good
throughout, so that reading across the upper line of days, from right to
left, and following with the second line in the same way, ending with
Akbal, the interval will be 4 months and 11 days between the consecutive
days. Another significant fact is that by counting 4 months and 11 days
from the first day of the year 1 Kan we reach 13 Ix; counting 9 months
and 2 days from the same date brings us to 13 Chicchan; 13 months and 13
days, to 13 Cib; and 1 year and 4 days, to 13 Manik, which corresponds
with the regular interval; it is therefore probable that there is an
error in the numerals over the first or left hand column.

It is apparent from the illustrations given that in numeral series of the
preceding type restorations can be made where not more than two numbers
in succession are wanting. Even three can generally be restored if the
numbers preceding and those following the break are distinct, but such
restorations should be cautiously made.

In the middle division of Plate 9 is a short series where the number over
the day column is wanting; moreover, there is uncertainty as to the
number of days in the column and as to the signification of the red
numerals, which are in pairs in Kingsborough's work instead of single as
usual. Is it possible to explain these uncertainties and to reduce them
to the usual simple form? Let us make the trial.

The days in the column are apparently the following: Ahau, Muluc, Ix,
Cauac, Kan. The symbols, except that for Cauac, are too plain to admit of
doubt, and there is no difficulty in