The total period of time, from the earliest date given, to the settlement of the country by the Spaniards, is 71 katuns. If the katun is estimated at twenty years, this equals 1420 years; if at twenty-four years, then we have 1704 years. All the native writers agree, and I think, in spite of the contrary statement of Bishop Landa, that we may look upon it as beyond doubt, that the last day of the 11th katun was July 15th, 1541. Therefore the one of the above calculations would carry us back to A. D. 121, the other to B. C. 173. The chief possibility of error in the reckoning would be from confusing the great cycles of 260 (or 312) years, one with another, and assigning events to different cycles which really happened in the same. This would increase the number of the cycles, and thus extend the period of time they appear to cover. This has undoubtedly been done in No. II. According to the reckoning as it now stands, six complete great cycles were counted, and parts of two others, so that the native at the time of the Conquest would have had eight great cycles to distinguish apart. I have not found any clear explanation how this was accomplished. We do not even know what name was given to this great cycle, nor whether the calendar was sufficiently perfected to prevent confusion in dates in the remote past. I find, however, two passages in the collection of ancient manuscripts, which I have before referred to as the _Codice Perez_, which seem to have a bearing on this point; but as the text is somewhat corrupt and several of the expressions archaic, I am not certain that I catch the right meaning. These passages are as follows:-- U hiɔil lahun ahau u ɔocol hun uuɔ katun, u zut tucaten oxlahunpiz katun ɔiban tu uichob tu pet katun; la hun uuɔ katun u kaba ca bin ɔococ u than lae, u hoppol tucaten; bay hoppci ca ɔib lae ca tun culac u yanal katun lae. Cabin ɔococ uaxac ahau lae u hoppol tucaten lae. (Page 90.) U hiɔil Lahun Ahau u ɔocol u nuppul oxlahunpez katun ɔiban u uichob tu pet tzaton lo hun (_sic_) uuɔ katun u kaba ca bin ɔococ u than lae, ca tun culac u yanal katun ca bin ɔococ uaxac Ahau lae; hu hoppol tucaten bay hoppci ca ɔib. (Page 168.) _Translation._ At the last of the tenth ahau katun is ended one doubling of the katun, and the return a second time of thirteen katuns is written on the face of the katun circle; one doubling of the katuns, as it is called, will then finish its course, to begin again; and when it begins, it is written that another katun commences: when the eighth katun ends it begins again (_i. e._, to count with this eighth as the first of the next "doubling").