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. Förstemann 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, from the picture inserted at this point in the series, that some important chronological event is indicated. Here also in the written characters over this picture is the symbol for 20. The last number given in the above addition may therefore, in order to correspond with the method of the codex, be written as follows: Twenty year periods. Years. Months. Days. 1 0 3 4 Continuing the addition in this way the result is as follows: