The mere handful that had at first entered the city had been increased by the army of Narvaez, so that when the news reached Cortez that Alvarado and the eighty odd men that had been left with him in the city were threatened with difficulty, he marched a well-appointed army of fourteen hundred men, besides two hundred Tlascalans, to his relief. Their retreat to Tlascala has already been described, the character of the brigantines has been discussed, as well as the absurd story of his having dug a slip or launching canal at Tezcuco, twelve feet broad and twelve feet deep. We have seen that the towns and villages said to have been built in the lake, and the still greater number of large towns on the main land, could only have been petty Indian hamlets, and that the central portions of the valley of Mexico would not have been habitable if the lakes of Mexico had been any thing more than evaporation ponds. And, lest I should venture too far, I will conclude this remark by adverting to the testimony of Diaz, which concedes that when his book was written the face of the country was substantially as it now is, and as I have already described it to be. But he endeavors to save the story of the Conquest by the shallow pretense that, during the few years that intervened between that event and the date of his history, the whole face of the country had completely changed.[48] The great mystery is why so large a body of Spaniards, if they really amounted to the number claimed by Cortez, should have retreated from the city at all, as they do not complain of being short of provisions. They had the great _teocalli_ for a fortress, on which they might have planted their cannon, and leveled the city in a few days, if not in a few hours, and the great Plaza in which to manoeuvre their cavalry and protect the Indians while leveling the rubbish of the broken walls. But a panic having seized them, and having escaped from the city by a badly-managed night retreat, ten months elapsed before the Spaniards, on the 13th of May, 1521, laid siege to the city. And with varying success the siege was continued just three months, until Guatemozin was taken prisoner, on the 13th of August, 1521, so that the siege was carried on in the midst of the rainy season, when the flats must have been covered with water, and the ditches well filled. No difficulty was experienced in bringing up his flat-boats to the sides of the muddy causeways, or in cutting off the supplies of provisions by water, or in breaking down the earthen aqueduct of Chapultepec, so that the Indians were finally subdued by the combined forces of hunger and thirst. When, the Aztecs were so enfeebled by want that they could no longer offer resistance, the Spaniards rushed into the town, seized the unresisting Guatemozin, and shouted victory. INDIAN WARFARE.