Proceeding southward, however, when we approach the vicinity of the City of Mexico, examples of carving appear, and it is quickly evident that the Aztecs gave great attention to this form of art. One of the most remarkable specimens is the so-called Calendar Stone dug up under the present city, and now in the Mexican National Museum. It has been called a sacrificial stone, but Bandelier thinks it may have served rather as the base for another stone, holding the rope of a captive doomed to the “gladiatorial” sacrifice. For my part I incline to the opinion that it is an astronomical affair. The date carved on the top is the 13th Acatl or +A.D.+ 1479 of our time, according to the accepted calculations. In the centre is a head, supposed to represent the sun, and around it are twenty figures, standing for the twenty days of the Mexican month. Then come eight divisions by what appear to be arrow-heads, four being extended farther toward the centre than the others and also curled up at the ends or flukes, and one of these four ending in an elaborate sort of bow-knot ornament which covers a wide space at what is now the lower edge as it stands. Each of the eight divisions is again divided by a kind of crown which is smaller than the smaller arrow-heads, and then there is a still further subdivision made by a dot, on a line with the base of the crown. This gives thirty-two points, or exactly the number of points on our mariner’s compass card, so that this carving can be “boxed” as any compass card can be. The N., E., and W., are more prominent than any other points but the S., which has the decoration referred to. Then come the N.E., S.E., S.W., and N.W., with each set of intermediate points diminishing in importance.[160] It looks as if our ancient Aztecs had found a mariner’s compass washed ashore and perpetuated it by thus carving it with mythological significance.[161] Stranger things than this have occurred among Amerinds. But I prefer to believe that the Aztec astronomer worked out the points of the compass for himself, for these directions exist of course in every land independent of the compass, and the moment the Amerind began to work in astronomy he was forced to recognise the thirty-two natural directions that were open to him. No doubt the Mayan and Mexican observatories were somewhat similar to that of the Shah Jahan at Jeypore in India, where circular stones of different sizes formed a part of the observing apparatus. The Mayan and Mexican astronomical knowledge was probably equal to any extant in the fourteenth century. [Illustration: THE AZTEC “CALENDAR” STONE From Bandelier’s _Archæological Tour_, published by the Archæological Institute of America ] [Illustration: AZTEC SCULPTURE, THE INDIO TRISTE From Bandelier’s _Archæological Tour_, published by the Archæological Institute of America ]