series of thirteen days. All the portion, included between the outer circumference of these 260 days and the external zone, has not been decyphered accurately. The external zone consists, except at the extremities, of a symbol twenty times repeated, and is alleged by Gama, a Mexican who first described and attempted to interpret the stone, to represent the milky way. The waving lines connected with it are supposed by this writer to represent clouds, while others imagine them to be the symbols of the mountains in which clouds and storms originated. These fanciful interpretations, however, are unavailable in all scientific descriptions, and Mr. Gallatin supposes the figures to be altogether ornamental.
The whole circle is divided into eight equal parts by the eight triangles R, which designate the rays of the sun. The intervals between these are each divided into two equal parts by the small circles indicated by the letter L. At the top of the vertical ray is found the hieroglyphic 13 Acatl, which shows that this stone applies to that year. It must be recollected that, although this Mexican calendar is in its arrangement the same for every year in the cycle, there was a variation at the rate of a day for every four years, between the several years of the cycle and the corresponding solar years. Gama presumes that this date of 13 Acatl was selected on account of its being the twenty-sixth year of the cycle and equally removed from its beginning and termination. Beneath this hieroglyphic, in correct drawings of the stone—but not in that of Gama which has been reproduced by Mr. Gallatin—will be found, between the letters Y and G, the distinct sign of 2, Acatl, and the ray above it points to the sign of the year 13 Acatl, which coincides with our 21st of December, and is undoubtedly the hitherto undetermined date of the winter solstice in the Mexican calendar. 5
The smaller interior circle, we have already said, contains the image of the sun, as usually painted by the Indians; and to it are united the four