We have thought it proper and interesting to preface the description of the calendar stone by the preceding account of the Aztec festival of the New Fire, which illustrates the mingled elements of science and superstition that so largely characterized the empire of Montezuma. The stone itself has engaged the attention, for years, of numerous antiquarians in Mexico, Europe and America, but it has received from none so perfect a description, as from the late Albert Gallatin, who devoted a large portion of his declining years to the study of the ancient Mexican chronology and languages. In the first volume of the Transactions of the American Ethnological Society he has contributed an admirable summary of his investigations of the semi-civilized nations of Mexico, Yucatan and Central America, and from this we shall condense the portion which relates to this remarkable monument.