The figure which thus reawakened patriotic sympathies in the descendants of Montezuma’s subjects is a rude disproportioned idol, strikingly contrasting with the elaborate hieroglyphical devices and well-proportioned figures and decorations which accompany the grotesque mask in the Casa de Piedra of Palenque. In the latter, the principal human figures present the remarkable profile of the ancient Central American race, as shown on a vase dug up among the ruins of Ticul (Fig. 75), with the prominent nose, retreating forehead and chin, and protruding under-lip, so essentially different from the features either of the Mexicans or northern Indians. The subject race on whom they tread are characterised by a diverse profile, with overhanging brows, a Roman nose, and a well-defined chin; while their costume is equally indicative of a different origin. But the sculpture of the Mexican Calendar Stone embodies evidence of an amount of knowledge and skill not less interesting for us than the mysterious hieroglyphics of the Palenque tablets; and was believed by Humboldt to indicate unmistakable relations to the ancient science of south-eastern Asia. Mr. Stephens has printed a curious exposition of the chronology of Yucatan, derived from native sources by Don Juan Pio Perez. From the correspondence of their mode of computing time with that adopted by the Mexicans, he assumes that it probably originated with them; but at the same time he remarks that the inhabitants of Mayapan, as the Peninsula was called at the period of Spanish invasion, divided time by calculating it almost in the same manner as their ancestors the Toltecs, differing only in the particular arrangement of their great cycles. Their year commenced on the 16th of July, an error of only forty-eight hours in advance of the precise day in which the sun returns there to the zenith, on his way to the south, and sufficiently near for astronomers who had to make their observations with the naked eye. Their calendar thus presents evidence of native and local origin. According to Humboldt, the Mexican year began in the corresponding winter half of the year, ranging from the 9th to the 28th of January; but Clavigero places its commencement from the 14th to the 26th of February.