een these columns as between the day
columns under them. The correctness of this supposition is shown by the
following additions: Starting with the first or left hand column on Plate
51_b_, we add successively the differences indicated by the corresponding
red and black numbers under the day columns. If this gives in each case
(save the two or three exceptions heretofore referred to) the numbers in
the next column to the right throughout the series, the demonstration
will be complete.

Years. Months. Days.
14 16 14 First column on Plate 51_b_.
8 17
-- -- --
15 7 11 Second column on Plate 51_b_.
8 17
-- -- --
15 16 8 Third column on Plate 51_b_.
8 17
-- -- --
16 7 5 Fourth column on Plate 51_b_.
8 17
-- -- --
16 16 2 Fifth column on Plate 51_b_.
7 8
-- -- --
17 5 10 Sixth column on Plate 51_b_.
8 18[319-1]
-- -- --
17 14 8 First column on Plate 52_b_.
8 17
-- -- --
18 5 5 Second column on Plate 52_b_.
8 17
-- -- --
18 14 2 Third column on Plate 52_b_.
8 17
-- -- --
19 4 19 Fourth column on Plate 52_b_.
8 17
-- -- --
19 13 16 First column on Plate 53_b_.
7 8
-- -- --
20 3 4 Second column on Plate 53_b_.

At this point in the original, instead of 20 in the year series, we find
a diamond shaped symbol, represented by 0 in our tables, with one black
dot over it. From this it would seem that when this codex was written the
Maya method of counting years was by periods of 20 each, as in the case
of the month days. Whether there is any reference here to the ahaues is
uncertain. I am inclined to think with Dr. Foerstemann that it was rather
in consequence of the use of the vigesimal system in representing
numbers. It would have been very inconvenient and cumbersome to represent
high numbers by means of dots and lines; hence a more practicable method
was devised. It is evident, fro