The story of this pyramid that has been thus far spared, is rectangular; and, facing north, south, east and west, in exact correspondence with the cardinal points, it measures sixty-four feet on its northern front above the plinth, and fifty-eight on the western. The distance between the plinth and frieze is about ten feet, the breadth of the frieze is three feet and a half, and the height of the cornice one foot and five inches. The most perfect portion is the northern front; and, here, the carving in relief, which is between three and four inches deep, is most distinctly visible. The massive stones,--some of which are seven feet eleven inches long, by two feet nine inches wide; five feet two inches long, and two feet six inches broad, and five feet long, two feet seven inches high, and four feet seven inches broad,--are all laid upon each other without cement, and kept together simply by the pressure and gravity of the general architecture. These dimensions of the fragments of so splendid an edifice will give the reader an idea of the labor and ingenuity which were employed in its construction. For it must be remembered, that not only was the Indian skill taxed in the design and shaping of the stones in the immediate neighborhood, but that the weighty materials were drawn from a considerable distance, and borne up a hill three hundred feet in height, without the use of horses. The terraces supporting the spiral path, and their bastion-like bulwarks, were subjects of equal labor; while the broad deep ditch, surrounding the whole, was in itself a work exacting the most patient industry. Few nations have probably devoted more time and toil to a work which was perhaps partly religious and partly defensive. These are the external works upon the Cerro of Xochicalco, but it appears from good authority, and from the report of the neighborhood, that the hill itself was partly hollowed into chambers. Some years since a party of gentlemen, under the orders of government, explored these subterranean retreats, and, after groping through dark and narrow passages, whose side walls are covered with a hard and glistening gray cement, they came to three entrances between two enormous pillars cut from the rock of which the hill is formed. Through these portals they entered a chamber, whose roof was a cupola of regular shape, built of stones placed in circles, while at the top of the dome was an aperture, which probably led to the surface of the earth or the summit of the pyramid. Nebel, who visited the ruins some years ago, relates an Indian tradition, that this aperture ascended immediately above an altar placed in this chamber, and that the sun's rays fell directly on the centre of the shrine when that luminary was vertical! CHAPTER VIII.