We had one clear day, which we devoted to taking Daguerreotype likenesses of the cura and two of the Mestizas; and, besides the great business of balls, bull-fights, Daguerreotyping, and superintending the morals of the padres, I had some light reading in a manuscript entitled, "Antigua Chronologia Yucateca," "Ancient Chronology of Yucatan; or, a simple Exposition of the Method used by the Indians to compute Time." This essay was presented to me by the author, Don Pio Perez, whom I had the satisfaction of meeting at this place. I had been advised that this gentleman was the best Maya scholar in Yucatan, and that he was distinguished in the same degree for the investigation and study of all matters tending to elucidate the history of the ancient Indians. His attention was turned in this direction by the circumstance of holding an office in the department of state, in which old documents in the Maya language were constantly passing under his eyes. Fortunately for the interests of science and his own studious tastes, on account of some political disgust he withdrew from public life, and, during two years of retirement, devoted himself to the study of the ancient chronology of Yucatan. It is a work which no ordinary man would have ventured to undertake; and, if general reputation be any proof, there was no man in the country so competent, or who could bring to it so much learning and research. It adds to the merit of his labours that, in prosecuting them, Don Pio stood alone, had none to sympathize with him, knew that the attainment of the most important results would not be appreciated, and had not even that hope of honourable distinction which, in the absence of all other prospects of reward, cheers the student in the solitary labours of his closet. The essay explains at large the principles imbodied in the calendar of the ancient Indians. It has been submitted for examination (with other interesting papers furnished me by Don Pio, which will be referred to hereafter) to a distinguished gentleman, known by his researches into Indian languages and antiquities, and I am authorized to say that it furnishes a basis for some interesting comparisons and deductions, and is regarded as a valuable contribution to the cause of science.