The first two lines, forming together a single period of 182 days, refer to a day III, as we see by the ending, and the last two to XIII, which undoubtedly refers to the III Chicchan and XIII Akbal, the days so significant in the preceding section. Hence an interval of 218 days (III Chicchan to XIII Akbal) is to be assumed between the second and third lines, with the addition of which interval each of the two periods extends over 400 days. The first and fourth series have the same difference; and the second and third correspond with one another in this respect. In the first and fourth the differences follow a rule, viz:--as if one were walking in a ring having on its edge the numbers 1 to 13, and kept stepping backward four numbers. The differences of the second and third series apparently do not follow any rule. Hence I think that the fourth series follows the third by mistake and ought rightfully to precede it. Only the fifth member in the first and second series has the same day VIII and the day V in the third and fourth series, otherwise the week-days of each series differ from those of the others. As I regard III Chicchan and XIII Akbal as unquestionably the starting-points, I will here give a table of the days on which each of the twenty-six members of each series must fall and at the same time I will indicate for each day its number from the beginning of the series. Accordingly the first 182 days present the following appearance:-- III 2. 1. 9. XII Ix 2. 14. IV Cauac 3. 15. V Ahau 4. 25. II Oc 5. 31. VIII Cib 6. 33. X Eznab 7. 44. VIII Muluc 8. 51. II Cib 9. 54. V Cauac 10. 66. IV Chuen 11. 74. XII Cauac 12. 78. III Akbal 13. 91. III Cib 14. 102. I Manik 15. 115. I Ahau 16. 126. XII Chuen 17. 127. XIII Eb. 18. 135. VIII Ahau 19. 141. I Cimi 20. 145. V Oc 21. 147. VII Eb 22. 160. VII Chicchan 23. 166. XIII Chuen 24. 172. V Caban 25. 180. I Chicchan 26. 182. III Manik In the same way I will tabulate the second group of 182 days, but in this case I shall place the fourth line before the third, which is probably correct, and which shows for the first time parallelism of the two rows:-- XIII 20.