The Calendar Stone.
The great sculptured monument known as the Calendar Stone or Stone of the Sun, is the most valuable object that has come down intact from the time of the Aztecs. It is a single piece of porphyry, irregular except for the sculptured face. It now weighs over twenty tons and it is estimated that the original weight was over twice as much. The sculptured disk is about twelve feet in diameter. This great stone was transported by men over many miles of marshy lake bottom before it could be placed in position in front of the Temple of the Sun in the temple enclosure that has just been described. The stone was doubtless thrown down from its original position by the soldiers of Cortez and may have been lost to sight. We know, however, that it was exposed to view about 1560 and was then buried by order of the archbishop of Mexico City lest its presence should cause the Indians to revert to their original pagan beliefs. It was rediscovered in 1790 and was afterwards built into the façade of the Cathedral where it remained until 1885, when it was removed to the nearby museum.
The Calendar Stone is not only a symbol of the sun’s face marked with the divisions of the year but it is a record of the cosmogonic myth of the Aztecs and the creations and destructions of the world. In the center is the face of the sun god, Tonatiuh, enclosed in the middle of the symbol called Olin. Tonatiuh is often represented by a much simpler sign of a circle with four or more subdivisions resembling those of a compass which are intended to represent the rays of the sun. Olin is one of the day signs and means movement, or perhaps earthquake. It has also been explained as a graphic representation of the apparent course of the sun during the year. The history of the world, according to the Aztecan myth, is divided into five suns or ages, four of which refer to the past and one to the present. The present sun is called Olin Tonatiuh because it is destined to be destroyed by an earthquake. The day signs of the four previous suns are represented in the rectangular projections of the central Olin symbol beginning at the upper right hand corner and proceeding to the left. They are 4 Ocelotl (jaguar); 4 Ehecatl (wind); 4 Quauhtli (rain); 4 Atl (water), and they refer to destruction, first, by jaguars, second, by a hurricane, third, by a volcanic rain of fire, fourth, by a flood. It is claimed by some that the year 13 Acatl (reed) recorded at the top of the monument between the reptile tails refers to the first year of the present sun. The fifth sun will end with the day 4 Olin, that is expressed in the central symbol already described. For this reason a fast was held on each recurrence of this day. Outside of the Olin symbol but between its arms are four hieroglyphs of uncertain meaning. Next to this area dealing with the great ages of the world comes a band of the twenty day signs of the Aztecan month. Outside of this band are several others which probably represent in a conventionalized manner the rays of the sun and the turquoise and eagle feathers with which the sun disk was believed to be decorated. Finally, outside of all, are two plumed monsters meeting face to face at the bottom of the disk. In each reptile face is seen a human face in profile. These reptiles are probably to be identified as the Xiuhcoatl or Fire Serpents.
The newly discovered National Stone pictures the Calendar Stone in vertical position on a mound and at the head of a flight of steps. The dates on the side of the stairway are 1 Tochtli and 2 Acatl, 1506 and 1507, indicating that the Calendar Stone was dedicated in connection with the New Fire Ceremony. The design on the back of this new-found monument pictures the eagle on the cactus, symbolic of the founding of Tenochtitlan. Other sculptures adorn the sides, the top, and the bottom of the stone.