The Aztecs were clever workers in gold and silver, and were acquainted with a number of arts that are lost to-day. Their picture writings bear witness to a clever fancy and fertile invention of symbols. The numerous idols show their skill in carving and a true artistic instinct. Many antiquities have been exhumed from the swampy soil on which the capital city is built, in making excavations for improvements. The National Museum is a treasure house of these relics and it would take a volume to describe them. The huge Sacrificial Stone, which is generally supposed to have been placed on the top of the great altar, is preserved there. It also houses the horrible image of the god Huitzilopochtli, and a varied assortment of inferior gods, goddesses, and other objects of worship. But the most celebrated antiquity—the one showing the greatest advancement—is the Calendar Stone. This stone was buried for centuries, and when resurrected was placed in the west tower of the cathedral. From this place it was removed a few years ago and placed in the museum. It is a mighty stone, eleven feet and eight inches in diameter, and weighs more than twenty tons. The Aztecs divided the year into eighteen months of twenty days each, and then arbitrarily added five days to complete the year. “Let us follow the cross, and if we have faith we will conquer,” was the motto on the banner of Cortez. It was with this spirit that he led his little band over the mountains and into the heart of the empire of Montezuma, late in the fall of 1519. He was met by that sovereign, tradition says, on the site of the present Hospital of Jesus, with every manifestation of friendliness. For several months they were the honoured guests of the Aztec chief, but at length the aggressions of the Spaniards changed friendship to hate and the Aztecs, rising in their wrath, chased the invaders from the city. Driven before the infuriated natives like sheep, they fled over the present road to the suburban village of Tacuba, and many were those who fell. This rout of the Spaniards has been painted with wonderful vividness by Gen. Lew Wallace in “The Fair God.” It was an awful night of despair, that first day of July, 1520, and the Spaniards who escaped named it La Noche Triste, “the sorrowful night.” The pursuit stopped at the little town of Popotla. In this village is a great cypress tree whose branches are blasted by the storms of centuries. For a moment the strong will of Cortez gave way and he sat down upon a stone under the spreading branches of this tree and wept. Whether he wept most for his fallen soldiers or disappointment over his ignominious defeat, we are not told by the chroniclers. This tree is now noted as _el arbol de la noche triste_, or “the tree of the sorrowful night.” A high iron fence protects the ancient relic from the souvenir vandals.